Skip to main content
OCLC Support

Why am I getting a browser warning of ERR CERT COMMON NAME INVALID after updating the SSL certificate on EZproxy

  • Users are getting a web browser warning about the EZproxy SSL certificate right after SSL certificate was updated.  The warning is ERR_CERT_COMMON_NAME_INVALID
  • The EZproxy prefix being used for HTTPS does not start with login. is an example.
  • The SSL certificate being used does not include the exact EZproxy name in either the CN or SAN fields only the wildcard entry is present.
Applies to
  • EZproxy all versions

Here is what you need to do to fix the issue:

  1. Update the SSL certificate to include both the exact EZproxy name and also the wild card of the EZproxy name.  Using the example about * and must be present on the SSL certificate.  It does not matter which value is in which field just both must be present or will generate the ERR_CERT_COMMON_NAME_INVALID browser warning
Additional information

The EZproxy prefix can also be updated to https://login. to resolve this issue as well.

Page ID