1. I forgot to add a script.
2. publish suggested to add a script "Flythrough"
3. the created exe in my first.cd folder tries to run the game using a script first.wdl which does not exist because publish created a script called first.c

This only happens if you try to publish a level without adding a script before and select the "new script" option in the publish dialog.

It is no big deal - but if you add a "new script" button... it should work.