>This is really simple I'm sure, but when a user clicks on the X in the window to close my application, I get the message "Cannot Quit VFP". How do I resolve that?
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This normally indicates that you need a shutdown routine, specified by ON SHUTDOWN - there are details in the FAQ.

>I also have one user who gets the following error message when starting my VFP Exe: "This program has performed an illegal operation and will be shut down." Our PC environment is all Dell systems that are supposed to be configured indentically, but this user receives these messages on a daily basis.
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This could be almost anything; I'd run memory diagnostics and disk diagnostics on it if you'e reasonably sure that it's hardware and software configuration is virtually identical to other systems that do not have this problem.