Thanks for your interest and time to answer my question.
Actually, I figured that out.
I had openned another spreadsheet where a macro disabled the usage of
cut&Paste. Somehow, even after the workbook was closed, the system assumed
that Cut&Paste should be disabled. To fix, you need to run a macro in the
Immediate" window of the "Visual Basic" editor. Use the function "Call" the
name of the tab (it can be any tab) with "." and the word "EnableCut&Paste"
I hope this can help others.
Thanks and take care,