Commented Issue: [Build 2.0.0858] Restore Layout exceptions in MVVMTestApp sample [15262]

Thank you for this great library -- it is very appreciated and working well for us except for a couple of issues.

We have been experiencing problems with restoring the layout and managed to re-create the issues with the MVVMTestApp.

Issue 1: Sometimes a tool window does not become visible after restoring the layout.

Issue 2: Sometimes we see crashes due to an exception in AvalonDock.Controls.LayoutFloatingWindowControl.FilterMessage in the WM_ACTIVATE case while trying to restore a layout with a floating window.

Steps to reproduce:

1. Build and run the MVVMTestApp
2. Drag the File Stats window off so it is a separate floating window.
3. Use File -> Open to open a text file document window.
4. Use Layout -> Save to save the layout.
5. Close the File Stats window by clicking on the 'X'.
6. Use Layout -> Load to try to load the layout again -- the File Stats window will appear and then vanish quickly. (This demonstrates issue 1).
7. Use File -> Open to open a different text file document window.
8. Use the document tabs to switch back and forth between the two files a couple of times.
9. Use Layout -> Load to try to load the layout again -- the app crashes with an exception in the WM_ACTIVATE message handler. (This demonstrates issue 2).
Comments: ** Comment from web user: adospace **

Thx for the report, but while the issue 1 is easy to see, I can't reproduce the issue 2. following your description everything seems to work fine, maybe I'm missing something.
Is the exception always thrown?