Charlie,

I believe this is by design. VARTYPE() will not trigger an error, but it will put error information into some of the internal memory locations that aerror() retrieves the information from. It works like this all the way back to VFP6.

Try this slightly different example, ignore the two errors as they occur

CLEAR ERROR   && Very good new command.
SET STEP ON 
LOCAL aErrArray[1]
? AERROR(aErrArray)
? int( "abc" )
? aerror( aErrArray )
? aErrArray[1], aErrArray[2], aErrArray[3] && 11 function argument type error NULL
? VARTYPE(xx)   && Returns "U"
? AERROR(aErrArray)
? aErrArray[1], aErrArray[2], aErrArray[3] && 11 Function argument type error XX
x = x + 1
? AERROR(aErrArray)
? aErrArray[1], aErrArray[2], aErrArray[3] && 12 Variable X not found X
? vartype( zz )
? AERROR(aErrArray)
? aErrArray[1], aErrArray[2], aErrArray[3] && 12 Variable ZZ not found ZZ
return

>It seems to me that AERROR() reports incorrect info. I'll report this properly, unless someone explains why it's not a bug. This behavior seems to be also present in VFP 8. Put aErrArray in the watch window and note its changes.