Function argument, value, or type is invalid

>>project that works fine to build interactively fails using BUILD EXE or the prject.build method. I cannot find this anywhere, but I am wondering if "errors" like array not found could be the cause,.
>>
>>It does not seem likely or logical, as the user presses ignore all, and the errors are hamless. but I cannot figure out the issue. The build attempt returns .f. and creatss a small stub .exe. Here is typical code, in which to all apperances it works -- there is no discernable difference in the time or processing apperance between the interactive build and the programmatic build.
>>
>>MODIFY PROJECT foo1 nowait
>> aproject = _vfp.Projects[1]
>> aproject.versionnumber = blah
>> aproject.versioncompany = blah
>> aproject.versionproduct = blah
>> aproject.versioncopyright = blah
>>
>> y = JUSTSTEM(aproject.name) + ".exe"
>> z = aproject.build(y, 3 , .f. , .f.) && filename, type, rebuildall, showerrors
>> aproject.close:
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>If you use aerror(), is there any error reported?