diff --git a/platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowManagerImpl.kt b/platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowManagerImpl.kt
index da1ff3bd4a4e..afebcd9a632b 100644
--- a/platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowManagerImpl.kt
+++ b/platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowManagerImpl.kt
@@ -46,6 +46,7 @@ import com.intellij.openapi.project.ex.ProjectEx
 import com.intellij.openapi.project.processOpenedProjects
 import com.intellij.openapi.ui.FrameWrapper
 import com.intellij.openapi.ui.Splitter
+import com.intellij.openapi.ui.ThreeComponentsSplitter
 import com.intellij.openapi.ui.popup.Balloon
 import com.intellij.openapi.ui.popup.JBPopupFactory
 import com.intellij.openapi.util.*
@@ -600,6 +601,7 @@ open class ToolWindowManagerImpl @NonInjectable @TestOnly internal constructor(
 
     if (isUnifiedToolWindowSizesEnabled()) {
       info.weight = layoutState.getUnifiedAnchorWeight(info.anchor)
+      LOG.debug("Activated tool window: ${info.id}, using ${info.anchor} unified weight of ${info.weight}")
     }
 
     if (source != null) {
@@ -1313,9 +1315,11 @@ open class ToolWindowManagerImpl @NonInjectable @TestOnly internal constructor(
           if (another != null && anchor.isUltrawideLayout()) { // split windows side-by-side, set weight of the entire splitter
             weight += another.new.weight
           }
+          LOG.debug("Setting ${item.entry.id} weight=${weight} from the saved layout")
           toolWindowPane.setWeight(anchor, weight)
         }
         if (item.old.sideWeight != item.new.sideWeight) {
+          LOG.debug("Setting ${item.entry.id} side weight ${item.new.sideWeight} from the saved layout")
           toolWindowPane.setSideWeight(item.entry.toolWindow, item.new.sideWeight)
         }
       }
@@ -2033,8 +2037,11 @@ open class ToolWindowManagerImpl @NonInjectable @TestOnly internal constructor(
     }
     else {
       // docked and sliding windows
+      val dockingAreaComponent = if (source.parent is Splitter) source.parent as Splitter else source
+      if (!dockingAreaIsInSplitterWithVisibleEditorArea(dockingAreaComponent)) {
+        return
+      }
       val anchor = info.anchor
-      val dockingAreaComponent: Component
       if (source.parent is Splitter) {
         var sizeInSplit = if (anchor.isSplitVertically) source.height else source.width
         val splitter = source.parent as Splitter
@@ -2044,20 +2051,37 @@ open class ToolWindowManagerImpl @NonInjectable @TestOnly internal constructor(
         info.sideWeight = getAdjustedRatio(partSize = sizeInSplit,
                                            totalSize = if (anchor.isSplitVertically) splitter.height else splitter.width,
                                            direction = if (splitter.secondComponent === source) -1 else 1)
-        dockingAreaComponent = splitter
-      }
-      else {
-        dockingAreaComponent = source
       }
       val toolWindowPane = getToolWindowPane(toolWindow)
       val toolWindowWeight = getAdjustedWeight(toolWindowPane, anchor, source)
       val dockingAreaWeight = getAdjustedWeight(toolWindowPane, anchor, dockingAreaComponent)
       info.weight = toolWindowWeight
       layoutState.setUnifiedAnchorWeight(anchor, dockingAreaWeight)
+      LOG.debug("Moved/resized tool window ${info.id}, updated weight=${toolWindowWeight}, docking area weight=${dockingAreaWeight}")
     }
     fireStateChanged(MovedOrResized, toolWindow)
   }
 
+  private fun dockingAreaIsInSplitterWithVisibleEditorArea(dockingAreaComponent: Component): Boolean {
+    val parentSplitter = dockingAreaComponent.parent as? ThreeComponentsSplitter
+    if (parentSplitter == null) {
+      LOG.warn(Exception("InternalDecoratorImpl/Splitter is not in a ThreeComponentsSplitter, " +
+                         "can't perform sanity checks, tool window info is not updated. " +
+                         "Actual parent = ${dockingAreaComponent.parent}"))
+      return false
+    }
+    val editorComponent = parentSplitter.innerComponent
+    if (editorComponent == null) {
+      LOG.info("Editor area is null, not updating tool window weights")
+      return false
+    }
+    if (!editorComponent.isVisible) {
+      LOG.info("Editor area is not visible, not updating tool window weights")
+      return false
+    }
+    return true
+  }
+
   private fun getAdjustedWeight(
     toolWindowPane: ToolWindowPane,
     anchor: ToolWindowAnchor,