Error: Entrust.net certificate renewal fails with error CSR111

Symptoms:

Entrust.net certificate renewal fails at stage 500 with the following error:

Post CSR failed with error: Invalid CSR – The certificate signing request (CSR) is invalid. The Common Name (CN) attribute is not formatted correctly. It must be a properly formatted IP address or domain name. (Error ID: CSR111). 

Cause:

The Common Name of the certificate is improperly formatted. This could be due to the CN starting with one character followed by a period.  

Resolution:

Correct the CN and restart the certificate processing from beginning.