1. Browse to the trickster.exe file in the Blumenmacht folder.
2. Right click trickster.exe and click Properties.
3. Click the Compatibility tab.
4. Select the "Run in 256 colors" check box.
Now Blumenmacht should run stable.
(This entry in ReadMe.txt is the only thing new in version 2.1b. Does somebody have an idea why the "Run in 256 colors" check box isn't selected on some computers?)