That doesn't say hidden worksheet, it says hidden workbook, and tells you it's the PERSONAL.XLSB workbook.

I don't save my macros to or use a personal macro workbook so anything I suggest would be just a guess.

My buddy, Google, showed me these when searching for "how to edit macro in personal.xlsb"

can't edit macro, says work book is hidden - Microsoft Community

Cannot Edit a Macro on a Hidden Workbook Error. How to Solve it?