diff --git a/platform/lang-impl/src/com/intellij/openapi/fileEditor/impl/TestEditorManagerImpl.java b/platform/lang-impl/src/com/intellij/openapi/fileEditor/impl/TestEditorManagerImpl.java
index 417c687b9247..a5348ac1a7f2 100644
--- a/platform/lang-impl/src/com/intellij/openapi/fileEditor/impl/TestEditorManagerImpl.java
+++ b/platform/lang-impl/src/com/intellij/openapi/fileEditor/impl/TestEditorManagerImpl.java
@@ -30,6 +30,7 @@ import com.intellij.testFramework.LightVirtualFile;
 import com.intellij.util.IncorrectOperationException;
 import org.jdom.Element;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.concurrency.Promise;
 import org.jetbrains.concurrency.Promises;
 
@@ -270,7 +271,7 @@ final class TestEditorManagerImpl extends FileEditorManagerEx implements Disposa
 
       @Override
       @NotNull
-      public FileEditorState readState(@NotNull Element sourceElement, @NotNull Project project, @NotNull VirtualFile file) {
+      public FileEditorState readState(@Nullable Element sourceElement, @NotNull Project project, @NotNull VirtualFile file) {
         throw new IncorrectOperationException();
       }
 
diff --git a/platform/lang-impl/src/com/intellij/openapi/fileEditor/impl/text/PsiAwareTextEditorProvider.java b/platform/lang-impl/src/com/intellij/openapi/fileEditor/impl/text/PsiAwareTextEditorProvider.java
index 07acbeb129c5..55b672944917 100644
--- a/platform/lang-impl/src/com/intellij/openapi/fileEditor/impl/text/PsiAwareTextEditorProvider.java
+++ b/platform/lang-impl/src/com/intellij/openapi/fileEditor/impl/text/PsiAwareTextEditorProvider.java
@@ -23,6 +23,7 @@ import com.intellij.psi.PsiDocumentManager;
 import org.jdom.Element;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class PsiAwareTextEditorProvider extends TextEditorProvider {
   private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.fileEditor.impl.text.PsiAwareTextEditorProvider");
@@ -37,11 +38,11 @@ public class PsiAwareTextEditorProvider extends TextEditorProvider {
 
   @Override
   @NotNull
-  public FileEditorState readState(@NotNull final Element element, @NotNull final Project project, @NotNull final VirtualFile file) {
+  public FileEditorState readState(@Nullable Element element, @NotNull final Project project, @NotNull final VirtualFile file) {
     final TextEditorState state = (TextEditorState)super.readState(element, project, file);
 
     // Foldings
-    Element child = element.getChild(FOLDING_ELEMENT);
+    Element child = element == null ? null : element.getChild(FOLDING_ELEMENT);
     if (child != null) {
       Document document = FileDocumentManager.getInstance().getCachedDocument(file);
       if (document == null) {
diff --git a/platform/platform-api/src/com/intellij/openapi/fileEditor/FileEditorProvider.java b/platform/platform-api/src/com/intellij/openapi/fileEditor/FileEditorProvider.java
index 0a19f2360dff..57cb883c149f 100644
--- a/platform/platform-api/src/com/intellij/openapi/fileEditor/FileEditorProvider.java
+++ b/platform/platform-api/src/com/intellij/openapi/fileEditor/FileEditorProvider.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.openapi.fileEditor;
 
 import com.intellij.openapi.extensions.ExtensionPointName;
@@ -24,6 +10,7 @@ import com.intellij.openapi.vfs.VirtualFile;
 import org.jdom.Element;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * Should be registered via {@link #EP_FILE_EDITOR_PROVIDER}.
@@ -71,7 +58,7 @@ public interface FileEditorProvider {
    * Use {@link FileEditorState#INSTANCE} as default implementation
    */
   @NotNull
-  default FileEditorState readState(@NotNull Element sourceElement, @NotNull Project project, @NotNull VirtualFile file) {
+  default FileEditorState readState(@Nullable Element sourceElement, @NotNull Project project, @NotNull VirtualFile file) {
     return FileEditorState.INSTANCE;
   }
 
diff --git a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/EditorHistoryManager.java b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/EditorHistoryManager.java
index c40b712289e0..b2be24582843 100644
--- a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/EditorHistoryManager.java
+++ b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/EditorHistoryManager.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.openapi.fileEditor.impl;
 
 import com.intellij.ide.ui.UISettings;
@@ -31,7 +17,6 @@ import com.intellij.openapi.project.DumbAwareRunnable;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.startup.StartupManager;
 import com.intellij.openapi.util.Comparing;
-import com.intellij.openapi.util.InvalidDataException;
 import com.intellij.openapi.util.Pair;
 import com.intellij.openapi.vfs.VfsUtilCore;
 import com.intellij.openapi.vfs.VirtualFile;
@@ -216,7 +201,7 @@ public final class EditorHistoryManager implements PersistentStateComponent<Elem
   /**
    * @return array of valid files that are in the history, oldest first. May contain duplicates.
    */
-  public synchronized VirtualFile[] getFiles(){
+  public synchronized VirtualFile[] getFiles() {
     final List<VirtualFile> result = new ArrayList<>(myEntriesList.size());
     for (HistoryEntry entry : myEntriesList) {
       VirtualFile file = entry.getFile();
@@ -306,8 +291,7 @@ public final class EditorHistoryManager implements PersistentStateComponent<Elem
         try {
           addEntry(HistoryEntry.createHeavy(myProject, e));
         }
-        catch (InvalidDataException | ProcessCanceledException e1) {
-          // OK here
+        catch (ProcessCanceledException ignored) {
         }
         catch (Exception anyException) {
           LOG.error(anyException);
diff --git a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/HistoryEntry.java b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/HistoryEntry.java
index ed8dd1bc7577..df20bf94779b 100644
--- a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/HistoryEntry.java
+++ b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/HistoryEntry.java
@@ -195,17 +195,14 @@ final class HistoryEntry {
       if (provider == null) {
         continue;
       }
-      if (Boolean.valueOf(providerElement.getAttributeValue(SELECTED_ATTR_VALUE))) {
+      if (Boolean.parseBoolean(providerElement.getAttributeValue(SELECTED_ATTR_VALUE))) {
         selectedProvider = provider;
       }
 
-      Element stateElement = providerElement.getChild(STATE_ELEMENT);
-      if (stateElement == null) {
-        throw new InvalidDataException();
-      }
-
       if (file != null) {
-        FileEditorState state = provider.readState(stateElement, project, file);
+        Element stateElement = providerElement.getChild(STATE_ELEMENT);
+        // due to backward compatibility null cannot be passed, so, use empty element
+        FileEditorState state = provider.readState(stateElement == null ? JDOMUtil.internElement(new Element("")) : stateElement, project, file);
         providerStates.add(Pair.create(provider, state));
       }
     }
diff --git a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/http/HttpFileEditorProvider.java b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/http/HttpFileEditorProvider.java
index b1d94a8f1e71..c564a10c4b98 100644
--- a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/http/HttpFileEditorProvider.java
+++ b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/http/HttpFileEditorProvider.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.openapi.fileEditor.impl.http;
 
 import com.intellij.openapi.fileEditor.FileEditor;
@@ -26,6 +12,7 @@ import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.openapi.vfs.impl.http.HttpVirtualFile;
 import org.jdom.Element;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * @author nik
@@ -44,7 +31,7 @@ class HttpFileEditorProvider implements FileEditorProvider, DumbAware {
 
   @Override
   @NotNull
-  public FileEditorState readState(@NotNull final Element sourceElement, @NotNull final Project project, @NotNull final VirtualFile file) {
+  public FileEditorState readState(@Nullable Element sourceElement, @NotNull Project project, @NotNull VirtualFile file) {
     return new TextEditorState();
   }
 
diff --git a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/text/TextEditorProvider.java b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/text/TextEditorProvider.java
index c3b425ace0bc..0fcc4bad5c4e 100644
--- a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/text/TextEditorProvider.java
+++ b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/text/TextEditorProvider.java
@@ -71,8 +71,11 @@ public class TextEditorProvider implements FileEditorProvider, DumbAware {
 
   @Override
   @NotNull
-  public FileEditorState readState(@NotNull Element element, @NotNull Project project, @NotNull VirtualFile file) {
+  public FileEditorState readState(@Nullable Element element, @NotNull Project project, @NotNull VirtualFile file) {
     TextEditorState state = new TextEditorState();
+    if (element == null) {
+      return state;
+    }
 
     try {
       List<Element> caretElements = element.getChildren(CARET_ELEMENT);
diff --git a/platform/testFramework/src/com/intellij/mock/Mock.java b/platform/testFramework/src/com/intellij/mock/Mock.java
index 394946c33d7b..4e4632a80419 100644
--- a/platform/testFramework/src/com/intellij/mock/Mock.java
+++ b/platform/testFramework/src/com/intellij/mock/Mock.java
@@ -681,7 +681,7 @@ public class Mock {
 
     @Override
     @NotNull
-    public FileEditorState readState(@NotNull Element sourceElement, @NotNull Project project, @NotNull VirtualFile file) {
+    public FileEditorState readState(@Nullable Element sourceElement, @NotNull Project project, @NotNull VirtualFile file) {
       throw new UnsupportedOperationException();
     }
 
diff --git a/plugins/properties/src/com/intellij/lang/properties/editor/ResourceBundleEditorProvider.java b/plugins/properties/src/com/intellij/lang/properties/editor/ResourceBundleEditorProvider.java
index 218e6f3468ca..80b35ec70c92 100644
--- a/plugins/properties/src/com/intellij/lang/properties/editor/ResourceBundleEditorProvider.java
+++ b/plugins/properties/src/com/intellij/lang/properties/editor/ResourceBundleEditorProvider.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.lang.properties.editor;
 
 import com.intellij.lang.properties.PropertiesImplUtil;
@@ -34,6 +20,7 @@ import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiManager;
 import org.jdom.Element;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class ResourceBundleEditorProvider extends FileTypeFactory implements FileEditorProvider, DumbAware {
   private static final ResourceBundleFileType RESOURCE_BUNDLE_FILE_TYPE = new ResourceBundleFileType();
@@ -73,7 +60,7 @@ public class ResourceBundleEditorProvider extends FileTypeFactory implements Fil
 
   @Override
   @NotNull
-  public FileEditorState readState(@NotNull Element element, @NotNull Project project, @NotNull VirtualFile file) {
+  public FileEditorState readState(@Nullable Element element, @NotNull Project project, @NotNull VirtualFile file) {
     return new ResourceBundleEditor.ResourceBundleEditorState(null);
   }
 
diff --git a/plugins/ui-designer-core/src/com/intellij/designer/DesignerEditorState.java b/plugins/ui-designer-core/src/com/intellij/designer/DesignerEditorState.java
index c57525c8903a..f7fb5cd08a6c 100644
--- a/plugins/ui-designer-core/src/com/intellij/designer/DesignerEditorState.java
+++ b/plugins/ui-designer-core/src/com/intellij/designer/DesignerEditorState.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2012 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.designer;
 
 import com.intellij.openapi.editor.Document;
@@ -22,6 +8,7 @@ import com.intellij.openapi.fileEditor.FileEditorStateLevel;
 import com.intellij.openapi.vfs.VirtualFile;
 import org.jdom.Element;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * @author Alexander Lobas
@@ -70,16 +57,15 @@ public class DesignerEditorState implements FileEditorState {
    * @see com.intellij.openapi.fileEditor.FileEditorProvider#readState(org.jdom.Element, com.intellij.openapi.project.Project, com.intellij.openapi.vfs.VirtualFile)
    */
   @NotNull
-  public static FileEditorState readState(@NotNull Element sourceElement, @NotNull VirtualFile file, double defaultZoom) {
+  public static FileEditorState readState(@Nullable Element sourceElement, @NotNull VirtualFile file, double defaultZoom) {
     double zoom = defaultZoom;
-
-    try {
-      zoom = Double.parseDouble(sourceElement.getAttributeValue(DESIGNER_ZOOM));
+    if (sourceElement != null) {
+      try {
+        zoom = Double.parseDouble(sourceElement.getAttributeValue(DESIGNER_ZOOM));
+      }
+      catch (Throwable ignored) {
+      }
     }
-    catch (Throwable e) {
-      // ignore
-    }
-
     return new DesignerEditorState(file, zoom);
   }
 
diff --git a/plugins/ui-designer/src/com/intellij/uiDesigner/editor/UIFormEditorProvider.java b/plugins/ui-designer/src/com/intellij/uiDesigner/editor/UIFormEditorProvider.java
index 24310a4db62e..8f8ae3f41780 100644
--- a/plugins/ui-designer/src/com/intellij/uiDesigner/editor/UIFormEditorProvider.java
+++ b/plugins/ui-designer/src/com/intellij/uiDesigner/editor/UIFormEditorProvider.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.uiDesigner.editor;
 
 import com.intellij.openapi.diagnostic.Logger;
@@ -29,6 +15,7 @@ import com.intellij.testFramework.LightVirtualFile;
 import com.intellij.util.ArrayUtil;
 import org.jdom.Element;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public final class UIFormEditorProvider implements FileEditorProvider, DumbAware {
   private static final Logger LOG = Logger.getInstance("#com.intellij.uiDesigner.editor.UIFormEditorProvider");
@@ -49,7 +36,7 @@ public final class UIFormEditorProvider implements FileEditorProvider, DumbAware
 
   @Override
   @NotNull
-  public FileEditorState readState(@NotNull final Element element, @NotNull final Project project, @NotNull final VirtualFile file){
+  public FileEditorState readState(@Nullable Element element, @NotNull final Project project, @NotNull final VirtualFile file){
     //TODO[anton,vova] implement
     return new MyEditorState(-1, ArrayUtil.EMPTY_STRING_ARRAY);
   }
diff --git a/python/ipnb/src/org/jetbrains/plugins/ipnb/editor/IpnbEditorProvider.java b/python/ipnb/src/org/jetbrains/plugins/ipnb/editor/IpnbEditorProvider.java
index e9f5f0a4ac52..ef4834bf2bd8 100644
--- a/python/ipnb/src/org/jetbrains/plugins/ipnb/editor/IpnbEditorProvider.java
+++ b/python/ipnb/src/org/jetbrains/plugins/ipnb/editor/IpnbEditorProvider.java
@@ -1,3 +1,4 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.plugins.ipnb.editor;
 
 import com.intellij.openapi.fileEditor.FileEditor;
@@ -6,10 +7,12 @@ import com.intellij.openapi.fileEditor.FileEditorProvider;
 import com.intellij.openapi.fileEditor.FileEditorState;
 import com.intellij.openapi.project.DumbAware;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.VirtualFile;
 import org.jdom.Element;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.plugins.ipnb.IpnbFileType;
 
 /**
@@ -32,10 +35,10 @@ public class IpnbEditorProvider implements FileEditorProvider, DumbAware {
 
   @NotNull
   @Override
-  public FileEditorState readState(@NotNull Element sourceElement, @NotNull Project project, @NotNull VirtualFile file) {
+  public FileEditorState readState(@Nullable Element sourceElement, @NotNull Project project, @NotNull VirtualFile file) {
     final IpnbEditorState state = new IpnbEditorState(-1, 0);
-    final Element child = sourceElement.getChild(SELECTED_CELL);
-    state.setSelectedIndex(child == null ? 0 : Integer.parseInt(child.getAttributeValue(ID)));
+    final Element child = sourceElement == null ? null : sourceElement.getChild(SELECTED_CELL);
+    state.setSelectedIndex(child == null ? 0 : StringUtil.parseInt(child.getAttributeValue(ID), 0));
     return state;
   }