Problem After an upgrade a connection filter may fail with the 'Subject Issuer Mismatch'

Resolution

You can check that this error message is misleading. There is no mismatch issue despite the error.

However this error can be thrown when the DH key is too small for the upgraded version of OpenSSL.

Check this by running a command such as 'openssl s_client -connect targetIp:port -cipher xxx'

and see if something like 'ssl3_check_cert_and_algorithm:dh key too small' is returned.