Gert
Just saw your report of how you solved your issue by reinstalling your software. Great news. Great job.
Your sharing of the outcome is appreciated by all.
If the problem should reoccur (hope not), please consider deleting the Adobe Premiere Elements Prefs file and, if that does not work, then delete the whole 13.0 Folder in which it exists.
Local Disk C
Users
Owner
AppData
Roaming
Adobe
Premiere Elements
13.0
and, in the 13.0 Folder, is the Adobe Premiere Elements Prefs File that you delete. And, if that does not work, then delete the whole 13.0 Folder in which the Adobe Premiere Elements Prefs file exists. Be sure to be working with Folder Option Show Hidden Files, Folders, and Drives active so that you can see the complete path cited.
Best wishes.
ATR