0x800f0922 could actually mean that the EFI system partition or the recovery partition are too small1. EFI partitions should be at least 500MiB in size, recommended size is 550MiB. You can resize partitions with tools like the AOMEI Partition Assistant which can be found on the Hiren's Boot CD PE.
Sometimes, Windows Server upgrades get stuck with error codes like 0x80073701 or 0x800f0922 and you can't solve it with the aforementioned solutions. This could mean Microsoft released an update which is incompatible with your particular system configuration. There's a tool from Microsoft called wushowhide.diagcab which you can hide updates with, which doesn't really get updated anymore2.
There's an Open Source tool called WuMgr with which you can block updates with3.
Install ISO: https://www.microsoft.com/de-de/evalcenter/evaluate-windows-server-2016-essentials#preinstall_24035
For Windows Server 2016 Essentials: You can convert to the full retail version by entering a retail, volume license, or OEM key in the commandslmgr.vbs.
https://docs.microsoft.com/en-us/windows-server/get-started/supported-upgrade-paths