While testing for [1], I've discovered, that my Office installation created Ole10Native containers with a trailing UTF16 label, filename, command, therefore I handle those now also. Furthermore I've replaced some obsolete parts (e.g. use of OPCPackage.getUnusedPartIndex instead of own file index check). My main Office installation suffered a problem with grooveex.dll [2], which crashed all object packager activations. I mention this here, as it might also affect other users, who regularly (windows-)update their machines. [1] https://stackoverflow.com/questions/62090939/apache-poi-unable-to-open-embedded-files [2] https://answers.microsoft.com/en-us/msoffice/forum/msoffice_onedrivefb-mso_win10/what-does-grooveexdll-do-exactly/36f971c1-69c1-4270-a1c9-685178b9e02b
applied via r1878730