diff --git a/platform/lang-impl/src/com/intellij/largeFilesEditor/editor/EditorModel.java b/platform/lang-impl/src/com/intellij/largeFilesEditor/editor/EditorModel.java
index 7a71cf7a691e..84b209262b55 100644
--- a/platform/lang-impl/src/com/intellij/largeFilesEditor/editor/EditorModel.java
+++ b/platform/lang-impl/src/com/intellij/largeFilesEditor/editor/EditorModel.java
@@ -269,6 +269,7 @@ public class EditorModel {
     }
 
     if (isNeedToShowCaret) {
+      ensureTargetCaretPositionIsInFileBounds(pagesAmountInFile);
       targetVisiblePosition.set(targetCaretPosition.pageNumber,
                                 targetVisiblePosition.verticalScrollOffset);  // we can't count the necessary offset at this stage
     }
@@ -685,6 +686,15 @@ public class EditorModel {
     return false;
   }
 
+  private void ensureTargetCaretPositionIsInFileBounds(long pagesAmount) {
+    if (targetCaretPosition.pageNumber < 0) {
+      targetCaretPosition.set(0, 0);
+    }
+    else if (targetCaretPosition.pageNumber >= pagesAmount) {
+      targetCaretPosition.set(pagesAmount, 0);
+    }
+  }
+
   private void normalizePagesInDocumentListEnding() {
     int visibleTargetPageIndex = tryGetIndexOfNeededPageInList(targetVisiblePosition.pageNumber);
     if (visibleTargetPageIndex == -1) {
diff --git a/platform/lang-impl/src/com/intellij/largeFilesEditor/file/FileAdapter.java b/platform/lang-impl/src/com/intellij/largeFilesEditor/file/FileAdapter.java
index b04e3d9f0186..6e76414bcf01 100644
--- a/platform/lang-impl/src/com/intellij/largeFilesEditor/file/FileAdapter.java
+++ b/platform/lang-impl/src/com/intellij/largeFilesEditor/file/FileAdapter.java
@@ -121,16 +121,12 @@ class FileAdapter {
    */
   @NotNull
   String getPageText(long pageNumber) throws IOException {
-
     randomAccessFileLock.lock();
     try {
-
-      /*DEBUG BEGIN*/
-      //java.util.Random rand = new java.util.Random(System.currentTimeMillis());
-      //if (true) try { Thread.sleep(rand.nextInt(100));} catch (InterruptedException e) {}
-      //if (rand.nextInt(10) < 1) throw new FileNotFoundException();
-      //try { Thread.sleep(10);} catch (InterruptedException e) {}
-      /*DEBUG END*/
+      long pagesAmount = getPagesAmount();
+      if (pageNumber < 0 || pageNumber >= pagesAmount) {
+        throw new IllegalArgumentException("pageNumber=" + pageNumber + ", pagesAmount=" + pagesAmount);
+      }
 
       long minProbStartPos;
       long startByte;