You are right There was a line in a code which I managed to miss :)

delete file *.fxp

adding

compile *.prg 

resolved the issue. DO &xprg with extension .prg or without DO (forceext(xprg, '')) as you suggested doesn't make a difference then.

>>A prg is not included in a project file.
>>Is it supposed to work at all when exe is launched from command line ?
>>It does work for exe build/run in IDE.
>>
>> do &xprg
>>
>>where xprg full path to prg file
>>
>>Set path to justpath(xprg)
>>or
>>cd justpath(xprg)
>>
>>don't help.
>>
>>The error :
>>File 'xyz.prg' does not exist
>
>Michael,
>
>You have to compile it first
>

>compile (xprg)
>do  (forceext(xprg, ''))
>