I checked the code and nothing obvious. I think when the instantiation fails the reference to the object remains. And then when the code tries to instantiate the second (or third) time, something is attempted to be "redefined". I did away with this attempt to instantiate the form 3 times. So, this will not be repeated.
Thank you.

>That are the values for aAppForms[nRow,3] and aAppForms[nRow,6]? it is possible one of these could the the 'THIS'?
>
>
>>>Hi,
>>>
>>>Do you know what would cause the error?
>>>

>>>cannot redefine THIS.
>>>

>>>
>>>TIA
>>
>>This is the code that caused the above error. Note that I am trying to create a reference to a window 3 times. What happens is the 1st time the actual error shows (dreaded ... error reading .... myprg.fxp)
>>
>>But on the 2nd and 3rd time, the error is "CANNOT REDEFINE THIS."
>>
>>Of course, I will remove this code that tries to instantiate the window 3 times. But I would to learn what causes it.
>>
>>Here is the code:
>>

>>FOR iTry = 1 TO 3
>>		
>>	*-- Start with No Problem
>>	lProblem = .F.
>>	TRY 
>>		aAppForms[nRow,5] = NEWOBJECT( aAppForms[nRow,3], aAppForms[nRow,6] )
>>	CATCH TO oError
>>		lProblem = .T.
>>		cCompName = GetEnv("COMPUTERNAME")
>>		TRY 
>>	 		STRTOFILE( TTOC(DATETIME()) + " Try: " + ALLTRIM(STR(iTry)) + " Failed to 
>>                    create NEWOBJECT() in OpenAppForm() Class: " + aAppForms[nRow,3] + " Lib: " + 
>>                    aAppForms[nRow,6]  + oError.message + CHR(13) + CHR(10), GetGlobal(2) + 
>>                   "create_object_problems.log", 1 )
>>	 	CATCH 
>>	 	ENDTRY 
>>	ENDTRY 
>>	IF lProblem
>>        	*-- Wait 2 seconds and then try again.
>>		INKEY(2)
>>		LOOP 
>>	ELSE 
>>		EXIT 			
>>	ENDIF 
>>ENDFOR 
>>