I have removed all the code - the problem persists.

I've removed all the macros - no difference

Martin, I downloaded your attached file, and had no problem pasting data into it, even after I unblocked the macros and enabled them (I didn't actually find any macros).

I'm on Office 365.

OMG, this means that your Office is different from mine .

Yes, it works for me with Excel 2010 but not with Excel 365 on Windows 11.

Just checking everything I can think of, I downloaded the attachment I uploaded to an earlier post and I cannot paste into it.

It looks like an Excel 365 issue ?

I was able to paste into the workbook using several different methods ( Ctrl-V, Rt Click and Paste, The PASTE selections on the QAT ).

I suspect this specific file is somehow corrupt on your computer and should be rebuilt into a new workbook.

Hmmm - when I download back the file I posted, I cannot paste into it.

Is it possible that Excel 365 is corrupt on my PC ?

I'd guess most likely. Due to an upgrade patch usually.

Thanks for the all help and ideas.
I've marked this as "Solved" even though it isn't really - its just closed as I don't think there's any more I can do, and I have a reasonable workaround using the clipboard dialog.
I will however post here again if I ever get to the bottom of it.