Hi JSPJ67,
I feel sorry if my second reply makes you confused, I should have explained clear and attached some screenshots.
Step1: Open Excel, click
File -> Options -> Add-ins.
Step2: Towards the bottom of the window, where it says
Manage, click the Go button.
Step3: In the dialog box, select all add-ins one by one, uncheck the box in front of its name.
Step4: Click
OK to save your changes, re-launch the Office client to check the results.

*You may need to re-check the
COM Add-ins in the list behind Manage.
Besides, click
Insert -> click the down triangle behind My Add-ins, you can find the Recently Used Add-ins lists here.
Click See All..., then you may find some add-ins below the MY ADD-INS tab on the
Office Add-ins panel. Hover on the add-ins -> click on the ellipsis -> click Remove to remove all of them one by one. Re-open Excel and check whether the issue disappears.


*You can make a note of the installed add-ins and try to re-install them one by one to check which add-in will cause this issue.
If the issue persists in Excel safe mode, I would like to give you another two suggestions:
- Run as an administrator to open Excel. Click
Start menu, Right-click on Excel icon -> More ->
Run as administrator.
Perform Online Repair Office to see the result.
Have a try and tell me the results.
Best Regards,
Hugo