For a customer, we've created a content type (document set) with multiple managed metadata fields. Within the docset, word-content types have been made available which inherit their metadata. We've noticed that when the sum of the selected MM values (filled in in SharePoint) is higher than 50, Word gives an error on 'missing properties - correct the invalid or missing properties...' in the DIP. As long as the sum is higher than 50, it is not possible to save the document. The user first has to adjust the docset MM, then update the doc, and then set the MM correct again... which isn't really userfriendly.
Is anyone aware of a limitation in office on maximum 50 MM values? Has anyone found a solution/workaround for this?