Hello!
Today I ran into rather strange issue: when I tried to add .NetFramework 3.5 to my virtual machines (Guest1 and Guest2, clustered) I got this error:
It looks like Windows doesn't see the Windows Server 2012 R2 iso file that was used for its own installation...
I then tried to add Windows Backup feature to rule out this possibility and all worked fine:
???
Thank you in advance,
Michael