Hi Andres.

>This has been working well for quite some time now. However, in the last few days, just out of the blue, it started failing with the following message: File 'Vartype.prg' does not exist. It happens only when running the EXE program; when running from the project, it is just fine.

In addition to the explanations offered by George and Sergey, another one is that the EXE was built in VFP 5. In that case, since VARTYPE() isn't recognized as a native function, VFP will insert a call to a user-defined function, which of course doesn't exist. Rebuild the EXE in VFP 6 with the "recompile all files" option checked and see if that helps.

Doug