--- a/widget/windows/TSFTextStore.cpp
+++ b/widget/windows/TSFTextStore.cpp
@@ -4788,17 +4788,27 @@ TSFTextStore::CreateAndSetFocus(nsWindow
   if (aContext.mIMEState.mEnabled == IMEState::PASSWORD) {
     MarkContextAsKeyboardDisabled(textStore->mContext);
     RefPtr<ITfContext> topContext;
     textStore->mDocumentMgr->GetTop(getter_AddRefs(topContext));
     if (topContext && topContext != textStore->mContext) {
       MarkContextAsKeyboardDisabled(topContext);
     }
   }
-  HRESULT hr = sThreadMgr->SetFocus(textStore->mDocumentMgr);
+
+  HRESULT hr;
+  {
+    // Windows 10's softwware keyboard requires that SetSelection must be
+    // always successful into SetFocus.  If returning error, it might crash
+    // into TextInputFramework.dll.
+    AutoSetTemporarySelection setSelection(textStore->SelectionForTSFRef());
+
+    hr = sThreadMgr->SetFocus(textStore->mDocumentMgr);
+  }
+
   if (NS_WARN_IF(FAILED(hr))) {
     MOZ_LOG(sTextStoreLog, LogLevel::Error,
       ("  TSFTextStore::CreateAndSetFocus() FAILED due to "
        "ITfTheadMgr::SetFocus() failure"));
     return false;
   }
   // Use AssociateFocus() for ensuring that any native focus event
   // never steal focus from our documentMgr.

--- a/widget/windows/TSFTextStore.h
+++ b/widget/windows/TSFTextStore.h
@@ -573,31 +573,55 @@ protected:
              aChangedSelection.mOffset == static_cast<uint32_t>(StartOffset());
     }
 
   private:
     TS_SELECTION_ACP mACP;
     WritingMode mWritingMode;
     bool mDirty;
   };
+
   // Don't access mSelection directly except at calling MarkDirty().
   // Use SelectionForTSFRef() instead.  This is modified immediately when
   // TSF requests to set selection and not updated by selection change in
   // content until mContentForTSF is cleared.
   Selection mSelectionForTSF;
 
   /**
    * Get the selection expected by TSF.  If mSelectionForTSF is already valid,
    * this just return the reference to it.  Otherwise, this initializes it
    * with eQuerySelectedText.  Please check if the result is valid before
    * actually using it.
    * Note that this is also called by ContentForTSFRef().
    */
   Selection& SelectionForTSFRef();
 
+  class MOZ_STACK_CLASS AutoSetTemporarySelection final
+  {
+  public:
+    AutoSetTemporarySelection(Selection& aSelection) : mSelection(aSelection)
+    {
+      mDirty = mSelection.IsDirty();
+      if (mDirty) {
+        mSelection.CollapseAt(0);
+      }
+    }
+
+    ~AutoSetTemporarySelection()
+    {
+      if (mDirty) {
+        mSelection.MarkDirty();
+      }
+    }
+
+ private:
+    Selection& mSelection;
+    bool mDirty;
+  };
+
   struct PendingAction final
   {
     enum ActionType : uint8_t
     {
       COMPOSITION_START,
       COMPOSITION_UPDATE,
       COMPOSITION_END,
       SET_SELECTION