Removing or uninstalling VBA-Dictionary... causes an unusable add-in warning/error message

[elGatoEnBotas]

I don't own a Mac but one of my clients does & I installed Dictionary class in my project with varying results according to him. After removing the class from my workbook, I am getting this strange error I haven't seen before: "OP

Experimentation 'We can't start this add in because it isn't set properly.'" How can we remove that? As it appears on all the Excel files I open, not just my .xlsm workbook. I tried deleting the addins folder for excel (https://answers.microsoft.com/en-us/msoffice/forum/all/cant-remove-an-add-on/a268b25f-03a9-4045-892b-95335ab45755). Didn't work.

[DecimalTurn]

I don't think this is related to VBA-Dictionary if you are getting this error when opening other Excel files without VBA macros.

This is likely a problem with Excel itself.
This post is probably related as it mentions "OP Experimentation": https://techcommunity.microsoft.com/t5/excel/new-excel-error-message/m-p/1436117