I have tried the solutions in other questions regarding installation failures of .NET Framework 4.8, but nothing have helped me so far.
The server is fully patched and rebooted. (Note! We use a WSUS but I do not know what updates are allowed or disallowed, maybe something is missing or I simply should ask the responsible person to allow .NET Framework 4.8 in the WSUS?)
As the server cannot reach the Internet, I have downloaded .NET Framework 4.8 offline installer from here:
https://go.microsoft.com/fwlink/?linkid=2088631
This is the error message from the install log (Note! I have tried to run the installation as Administrator):
Wait for Item (x64-Windows10.0-KB4486153-x64.cab) to be available
x64-Windows10.0-KB4486153-x64.cab is now available to install
Creating new Performer for Exe item
Created new ExePerformer for Exe item
Action: Performing Action on Exe at C:\5a9f17874cff9e1d385125\x64-Windows10.0-KB4486153-x64.cab
Launching CreateProcess with command line = dism.exe /quiet /norestart /online /add-package /packagepath:"C:\5a9f17874cff9e1d385125\x64-Windows10.0-KB4486153-x64.cab"
Exe log file(s) :
C:\Windows\logs\cbs\CBS.log
Log File C:\Windows\logs\cbs\CBS.log exists and will be added to the Watson upload list
Exe (C:\5a9f17874cff9e1d385125\x64-Windows10.0-KB4486153-x64.cab) failed with 0x80092004 - Cannot find object or property. .
Exe Log File: CBS.log
PerformOperation on exe returned exit code 2148081668 (translates to HRESULT = 0x80092004)
Action complete
Error 0x80092004 is mapped to Custom Error:
OnFailureBehavior for this item is to Rollback.
Action: Performing actions on all Items
Restart manager will not be used since the current operation is not install.
Action complete
Action complete
Final Result: Installation failed with error code: (0x80092004), "Cannot find object or property. " (Elapsed time: 0 00:02:46).
I have checked the temporary folder (in this case C:\5a9f17874cff9e1d385125) and the cab file is there.
I have tried to install the cab file separately by downloading it from Microsoft Update Catalog (https://www.catalog.update.microsoft.com/Search.aspx?q=4486153). It must be the last file in this case. But the install fails without any information. I guess there is a log somewhere, have not got that far yet.
Does anyone have any clues to what I'm doing wrong here?