I have developed an add-in with Excel VBA that has been working fine for the last few months. Within the last two weeks I have been getting error 400 and error 1004 for "Unable to set the Installed property of the Addin class". This error does not happen on every machine and some times it fixes itself. I have tried repairing both the add-in and the sheet that is calling it. Any ideas why after months of using the add-in it is giving me this error?
Error happens on .installed. This code is called with-in the "Workbook_Open" event.
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