SYMPL Core Sp license upgrade fails with "Error while upgrading the license: Padding is invalid and cannot be removed."

A customer reported, that the license upgrade with the *.scuf we provided did not succeed.
He needed to transfer the dongle file from his iPhone to a Windows computer, to be able to upload it to the SYMPL Core Sp.
The error message given by SYMPL Core Sp is "Error while upgrading the license: Padding is invalid and cannot be removed."

Based on the error message we assume the transfer from one device and operating system (OS) to another device and OS lead to a corrupted file.

Solution: we provided the same *.scuf file compressed in a .zip file.
Customer reported, the license upgrade now was successful.
Currently we have no more details about how exactly the transfer was done. But this KB article might help in future cases.