VFP 7

When I try to debug a form (invokde the debugger) I get the error messag

Cannot lock table for myoperation

I cannot find the error message in the help file.

All I did was change code in methods to get correct year to display in the form.
I then wanted to fix local variables for a report but cannot use the debugger (or even Run the form with out the above error message displaying many times.

What is causing this error and how do I fix it?

TIA for any help.