It usually means that the compiled version of code (for example .fxp) is out of sync with the real source code files (for example .prg). If you delete all .fxp files, VFP automatically recreates them if you run the .prg. You can also hit the RECOMPILE ALL button in the project manager.


http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dv_foxhelp/html/errsource_code_out_of_date.asp