Hi Bill,
Which software are you using and what version? It seems as though you are using Visual Basic.
What is your ultimate goal in your application?
I recommend you have a look at the help file located at Start >> Programs >> National Instruments >> Vision >> Documentation >> NI Vision.
In that folder there is a file called cwimaq.chm, which is a help file you can use for using Vision functions in VB.
If you can provide me with more details I can help you more.
Typically that error is when you are trying to call a function that doesn't work for that object. The help file should give you more information about what functions you can call.
Rishi L
National Instruments
Applications Engineer