Viewer does not start sometimes

[vMeijin]

Hello,
thanks for your effort to continue development on this useful tool. I tried using your version, since the latest version 1.8 has an issue with mirror-rotated cells which are displayed "hollow". It seems you fixed this bug or at least it does not occur here anymore.

However, when I try to start the viewer it sometimes (maybe 25% of the time) does not open a window and just ends after printing 'Picking "..." as topcell.' I do not have this issue with version 1.8, which always starts.

Have you encountered this problem before or do you have an idea how to fix it? Unfortunatly, I am not allowed to send you my files for testing.