Generally there is a clue available when you examine the code. Since you haven't posted the code that fails it is up to you to fix.

Is the file created on the fly before the code tries to open it?

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Andrew Lockton
Chrysalis Design, Melbourne Australia

That's the thing. It's literally all of my code. I have a few dozen macros and all of them trip up with this error, even simple ones that just do textual work rather than manipulating files, and even ones that don't refer to other macros. I can set a breakpoint at the beginning of a macro and this error still appears. It was working this morning, and now it's not!