This error might show up after we upload a Chained Server certificate with Server cert, Intermediate/Root cert part of the chain.
The reason for this error is that the Signature Algorithm in root certificate is md2WithRSAEncryption.
MD2 is disabled as it is not a secure hash algorithm. Hence we are seeing the error on the Clearpass Server.
In order to address this, we need to get certificate from a different root certificate Authority or different vendor.