IIS8 Centralized Certificates Not Recognizing Certs ("The specified private key password is not correct.")

In regards to the issue you are seeing where it responds with the file system could not find the file specified, we had a similar issue.

Our certificate manager always uses Linux/OpenSSL to create the PFX files, and the output file have missing header information that OpenSSL doesn't care about. The fix for us was to import the cert into CertMgr.msc on Windows and then re-export it to a new PFX; once imported into the CCS, all worked as it should.