Roadmap Legend panel is missing after Show default panels-layout

[shaswin]

Affected version: Ple4Win v4.2.0
Reproducible: Always

Steps to reproduce this issue:
Step 1: Open a fully processed project file with Ple4Win;
Step 2: Select in the menu bar View -> Other panels -> Roadmap Legend. The Roadmap LEgend panel will be active then;
Step 3: Click on the "Show default panels-layout."-button in the View toolbar or select View -> Default View;

After step 3 the Roadmap Legend will disappear from the screen. If you go to View -> Other panels -> Roadmap Legend, you will see that the Roadmap is selected, but the panel is missing now (not viewable).

All other active panels are working correctly and will be set on default view.