Today I observed an issue on a notebook where Excel 2016 was installed and then removed, going back to Excel 2013.
After this operation, workbooks having a Power Pivot data model were working correctly by navigating data in PivotTables, but any operation in the Power Pivot window (such as adding columns, tables, or editing measures) was failing. The error was a TYPE_E_CANTLOADLIBRARY and it was caused by a type library not removed uninstalling Excel 2016.
I solved the problem by removing the following key from the registry
(WARNING: DON’T TOUCH THE WINDOWS REGISTRY IF YOU DON’T KNOW WHAT YOU ARE DOING – use the following link to get more detailed instructions and always do a backup first).
I found this article that describes the problem as a possible issue in all the versions of Excel!