Thanks, Tom...
Scary problem! Do you think that could happen even if I run the application files outside of the app (DO main.prg instead of DO MyApp.app)?
Mark

>IF the tmpfiles setting in config.fpw on the machine that the project is built is on a drive that doesn't exist on the users machine, you will get this error.
>
>Make sure your pc where you build the app reference c: for tmpfiles
>
>
>
>>Cetin,
>>Thanks for your reply! There is no config.fpw, and here's the trick with the project:
>>When I run the application at the command line, with DO main.prg (as opposed to DOing the .app), I still get the error at various places.
>>Once, when I removed a MODIFY WINDOW xxx FONT xxx command, the errors stopped, but then for no reason, they started again. Very confusing!
>>Mark
>>
>>>Mark,
>>>In config.fp(w) and project file (app.pjx) check for a reference to a nonexistant drive.
>>>Cetin