diff --git a/platform/core-impl/src/com/intellij/ide/plugins/cl/PluginClassLoader.java b/platform/core-impl/src/com/intellij/ide/plugins/cl/PluginClassLoader.java
index f60fb9c20978..0e660f2870e3 100644
--- a/platform/core-impl/src/com/intellij/ide/plugins/cl/PluginClassLoader.java
+++ b/platform/core-impl/src/com/intellij/ide/plugins/cl/PluginClassLoader.java
@@ -52,6 +52,8 @@ public final class PluginClassLoader extends UrlClassLoader implements PluginAwa
 
   private final int instanceId;
 
+  private volatile int state = ACTIVE;
+
   public PluginClassLoader(@NotNull List<URL> urls,
                            @NotNull ClassLoader @NotNull [] parents,
                            @NotNull PluginDescriptor pluginDescriptor,
@@ -90,6 +92,16 @@ public final class PluginClassLoader extends UrlClassLoader implements PluginAwa
     }
   }
 
+  @ApiStatus.Internal
+  public int getState() {
+    return state;
+  }
+
+  @ApiStatus.Internal
+  public void setState(int state) {
+    this.state = state;
+  }
+
   @Override
   public int getInstanceId() {
     return instanceId;
diff --git a/platform/core-impl/src/com/intellij/ide/plugins/cl/PluginAwareClassLoader.java b/platform/extensions/src/com/intellij/ide/plugins/cl/PluginAwareClassLoader.java
similarity index 78%
rename from platform/core-impl/src/com/intellij/ide/plugins/cl/PluginAwareClassLoader.java
rename to platform/extensions/src/com/intellij/ide/plugins/cl/PluginAwareClassLoader.java
index 93521a3ffe96..9eed9d86ed05 100644
--- a/platform/core-impl/src/com/intellij/ide/plugins/cl/PluginAwareClassLoader.java
+++ b/platform/extensions/src/com/intellij/ide/plugins/cl/PluginAwareClassLoader.java
@@ -3,12 +3,16 @@ package com.intellij.ide.plugins.cl;
 
 import com.intellij.openapi.extensions.PluginDescriptor;
 import com.intellij.openapi.extensions.PluginId;
+import org.intellij.lang.annotations.MagicConstant;
 import org.jetbrains.annotations.NotNull;
 
 import java.net.URL;
 import java.util.Collection;
 
 public interface PluginAwareClassLoader {
+  int ACTIVE = 1;
+  int UNLOAD_IN_PROGRESS = 2;
+
   @NotNull PluginDescriptor getPluginDescriptor();
 
   @NotNull PluginId getPluginId();
@@ -22,4 +26,7 @@ public interface PluginAwareClassLoader {
   long getLoadedClassCount();
 
   @NotNull Collection<URL> getUrls();
+
+  @MagicConstant(intValues = {ACTIVE, UNLOAD_IN_PROGRESS})
+  int getState();
 }
diff --git a/platform/extensions/src/com/intellij/openapi/extensions/impl/ExtensionPointImpl.java b/platform/extensions/src/com/intellij/openapi/extensions/impl/ExtensionPointImpl.java
index fb3a0268ac0b..2b9a491903c9 100644
--- a/platform/extensions/src/com/intellij/openapi/extensions/impl/ExtensionPointImpl.java
+++ b/platform/extensions/src/com/intellij/openapi/extensions/impl/ExtensionPointImpl.java
@@ -3,6 +3,7 @@ package com.intellij.openapi.extensions.impl;
 
 import com.intellij.diagnostic.ActivityCategory;
 import com.intellij.diagnostic.StartUpMeasurer;
+import com.intellij.ide.plugins.cl.PluginAwareClassLoader;
 import com.intellij.openapi.Disposable;
 import com.intellij.openapi.components.ComponentManager;
 import com.intellij.openapi.diagnostic.Logger;
@@ -465,6 +466,9 @@ public abstract class ExtensionPointImpl<@NotNull T> implements ExtensionPoint<T
   // (EP->adapter in one thread, adapter->EP in the other thread)
   private synchronized @Nullable T processAdapter(@NotNull ExtensionComponentAdapter adapter) {
     try {
+      if (!checkThatClassloaderIsActive(adapter)) {
+        return null;
+      }
       return adapter.createInstance(componentManager);
     }
     catch (ExtensionNotApplicableException ignore) {
@@ -488,6 +492,10 @@ public abstract class ExtensionPointImpl<@NotNull T> implements ExtensionPoint<T
                                      @NotNull Class<T> extensionClassForCheck,
                                      @NotNull List<? extends ExtensionComponentAdapter> adapters) {
     try {
+      if (!checkThatClassloaderIsActive(adapter)) {
+        return null;
+      }
+
       boolean isNotifyThatAdded = listeners != null && listeners.length != 0 && !adapter.isInstanceCreated() && !isDynamic;
       // do not call CHECK_CANCELED here in loop because it is called by createInstance()
       T extension = adapter.createInstance(componentManager);
@@ -526,6 +534,16 @@ public abstract class ExtensionPointImpl<@NotNull T> implements ExtensionPoint<T
     return null;
   }
 
+  private static boolean checkThatClassloaderIsActive(@NotNull ExtensionComponentAdapter adapter) {
+    ClassLoader classLoader = adapter.getPluginDescriptor().getPluginClassLoader();
+    if (classLoader instanceof PluginAwareClassLoader &&
+        ((PluginAwareClassLoader)classLoader).getState() != PluginAwareClassLoader.ACTIVE) {
+      LOG.warn(adapter + " not loaded because classloader is being unloaded");
+      return false;
+    }
+    return true;
+  }
+
   // used in upsource
   // remove extensions for which implementation class is not available
   @SuppressWarnings("unused")
diff --git a/platform/platform-impl/src/com/intellij/ide/plugins/DynamicPlugins.kt b/platform/platform-impl/src/com/intellij/ide/plugins/DynamicPlugins.kt
index 5a53818c5b8f..14fc678c26bd 100644
--- a/platform/platform-impl/src/com/intellij/ide/plugins/DynamicPlugins.kt
+++ b/platform/platform-impl/src/com/intellij/ide/plugins/DynamicPlugins.kt
@@ -15,6 +15,7 @@ import com.intellij.ide.IdeEventQueue
 import com.intellij.ide.SaveAndSyncHandler
 import com.intellij.ide.actions.RevealFileAction
 import com.intellij.ide.impl.ProjectUtil
+import com.intellij.ide.plugins.cl.PluginAwareClassLoader
 import com.intellij.ide.plugins.cl.PluginClassLoader
 import com.intellij.ide.ui.TopHitCache
 import com.intellij.ide.ui.UIThemeProvider
@@ -473,10 +474,14 @@ object DynamicPlugins {
 
       app.messageBus.syncPublisher(DynamicPluginListener.TOPIC).beforePluginUnload(pluginDescriptor, options.isUpdate)
       IdeEventQueue.getInstance().flushQueue()
-      // must be after flushQueue (e.g. https://youtrack.jetbrains.com/issue/IDEA-252010)
       app.runWriteAction {
+        // must be after flushQueue (e.g. https://youtrack.jetbrains.com/issue/IDEA-252010)
         val forbidGettingServicesToken = app.forbidGettingServices("Plugin $pluginId being unloaded.")
         try {
+          // https://youtrack.jetbrains.com/issue/IDEA-245031
+          // mark plugin classloaders as being unloaded to ensure that new extension instances will be not created during unload
+          setClassLoaderState(pluginDescriptor, PluginClassLoader.UNLOAD_IN_PROGRESS)
+
           processLoadedOptionalDependenciesOnPlugin(pluginId) { mainDescriptor, subDescriptor ->
             // must be before unloadPluginDescriptorNotRecursively as this method nullize classloader
             val classLoader = (subDescriptor ?: mainDescriptor).pluginClassLoader as? PluginClassLoader
@@ -587,6 +592,11 @@ object DynamicPlugins {
         FUCounterUsageLogger.getInstance().logEvent("plugins.dynamic", eventId, fuData)
       }
     }
+
+    if (!classLoaderUnloaded) {
+      setClassLoaderState(pluginDescriptor, PluginAwareClassLoader.ACTIVE)
+    }
+
     return classLoaderUnloaded
   }
 
@@ -1107,4 +1117,11 @@ private fun unloadClassLoader(pluginDescriptor: IdeaPluginDescriptorImpl, timeou
   val watcher = GCWatcher.tracking(pluginDescriptor.classLoader)
   ClassLoaderConfigurator.setPluginClassLoaderForMainAndSubPlugins(pluginDescriptor, null)
   return watcher.tryCollect(timeoutMs)
+}
+
+private fun setClassLoaderState(pluginDescriptor: IdeaPluginDescriptorImpl, state: Int) {
+  (pluginDescriptor.classLoader as? PluginClassLoader)?.state = state
+  for (dependency in (pluginDescriptor.pluginDependencies ?: return)) {
+    dependency.subDescriptor?.let { setClassLoaderState(it, state) }
+  }
 }
\ No newline at end of file