Did you look up the message in help? Specify dates in umabmbiguous format. It has nothing to do with COM or COM+, but is VFP error.

>I have a dll en com+, in my development pc
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>From a small prg I try
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>
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>SET STEP ON
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>SET CENTURY ON
>SET CENTURY TO 20 ROLLOVER 30
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>obj = CREATEOBJECTEX( {181848BA-43E1-464A-A93C-53C3C9CA6999}, "" )
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>a=1
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>
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>and this is the error message I get
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>Ambiguous date/datetime constant. Use the format:
>{yyyy-mm-dd[,][hh[:mm[:ss]][a|p]]}
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>What should I do to instantiate the object?