When you updated the certificates, did you do the entire certificate request process on PC? -Or did you just re-download the same certificate and try to install it? Have you tried to run certmgr and remove the old certificates with that (and then install the certificate again?)
If not, please try run certmgr: Start>Run>CMD -In the command prompt, type “certmgr” (without quotation marks) and you should see this window:
After removing, then do the entire certificate request process from the PC you are working on.
This should correct the issue for the blank project at least.