This has to be to most annoying issue I have fixed in the last few months, I mean seriously! So the server manager on one of my Windows 2008 R2 SP1 server decided that it would not let me add any Roles or Features and the error that I was presented with was
"A required certificate is not within its validity period 0x800b0101"
I had similar issues with the Server Manager not opening on other servers in the past and I was able to fix that with the required solution and I have another post on the site with detailed troubleshooting on that but here it did not work.
So as a rule of thumb I downloaded and ran the Microsoft Update Readiness Tool and in the logs which the tools generates under "C:\WINDOWS\LOGS\CBS" in the file "CheckSUR.log" i saw the below errors..
Checking Windows Servicing Packages
hecking Windows Servicing Packages
Checking Package Manifests and Catalogs(w) CBS Catalog Expired 0x800B0101 servicing\Packages\Package_2_for_KB2705219~31bf3856ad364e35~amd64~~126.96.36.199.cat (w) CBS Catalog Expired 0x800B0101 servicing\Packages\Package_3_for_KB2705219~31bf3856ad364e35~amd64~~188.8.131.52.cat (w) CBS Catalog Expired 0x800B0101 servicing\Packages\Package_5_for_KB2722913~31bf3856ad364e35~amd64~~184.108.40.206.cat (w) CBS Catalog Expired 0x800B0101 servicing\Packages\Package_for_KB2731847_SP1~31bf3856ad364e35~amd64~~220.127.116.11.cat
Some people spoke about changing the system time and all that nonsense but it didn't make any sense to me and I was determined to fix this error and at the end of it I found an update which after running it fixed the issue that I was experiencing!
Download the update and run it on the server which will fix the above error and thus allowing the server manager to function how it should!