So, installing .net 3.5 on a window server is not really that hard and normally you just need to run the command Add-WindowsFeature NET-Framework-Core -Source d:\sources\sxs, but recently I had a few machines where this simply failed with error code 0x800f0922 or other vague error code. Looking up these errors provided me with more than enough results in DuckDuckGo, but unfortunately none of them provided a solutions. In a few cases I even ended up with reinstalling the OS. And that was also the only lead I had. Clean installed machines didn’t had this issue, but machines that already received updates had the issue. Hmm…
So eventually I had found the cause, it looked like the .net 3.5 installation had a conflict with the .net 4.x installation that comes enabled by default and also is needed for features like PowerShell 5.1 that are quite important for sysadmins. The solution was simple:
- Remove .net 4.x
- Enable .net 3.5 (using the source parameter)
- Enable .net 4.x again, because you know… PowerShell.
Now, this might not work for everybody, but it was one of the solution I didn’t found when ducking (or googling) it for these error’s and it’s one more solution you could try.