How can I resolve proxy errors?


Many websites are now using SSL encryption (indicated by the https:// in the website link) to make user data more secure. Credo has now moved exclusively to the secure version. For the process to set up your proxy to accomodate https, see our Proxy Help page here

Here are some common proxy issues when transitioning to https. 

1. "To use as a starting point..."

This message indicates that the configuration stanza for Credo needs to be updated. Find the updated version on our Proxy Help page.

2. Page loads, but without formatting

This indicates that your proxy is blocking Credo's CSS (style sheet). To resolve this, update to the latest config (on our Proxy Help page), particularly the "NeverProxy" directives at the bottom. For WAM proxy, make sure to use the explicit subdomains rather than a wildcard (ie, do not use * in your WAM forward table.

3. "Connection Refused" - Consistent error messages:

  • This can happen when there is no proxy SSL certificate in place. Documentation on certificates can be found on OCLC's site here. There's also a free SSL certificate option available here.
  • This could be related to a proxy firewall restriction on the secure version of the site. If you're able to open a web browser on your proxy server, see if you can reach in this browser. If not, your network admin will likely need to whitelist this URL.
  • We also see this issue when the proxy server can't handle a redirect. Try updating the proxied URL to the latest version (, which may resolve the issue.

4. "Connection Refused" - First log-in only

If you see this message the first time you log in, but subsequent log-ins work correctly, this is often caused by the proxy server caching old information. Try clearing the proxy server's cache or stopping and restarting the proxy service to clear it. 

If the "Connection Refused" issue persists, and you are using EZ Proxy 6 or above, try this suggestion from OCLC:

Add the word “Interface” followed by your internal EZproxy IP address to the top of the Credo stanza in your config.txt file. This is how it should appear:

Title Credo Reference

5. "Insecure Connection" or "Connection Untrusted"

This indicates that your certificate is configured incorrectly. For details, click the "Advanced" or "Technical Details" option on the warning page. Typically, this can be resolved by adding to the certificate as a supported domain. 

6. "Max Virtual Hosts exceeded", or connection timing out (EZ Proxy by port only) 

These issues are related to the new port number assigned to Credo when you update your proxy config with the latest Credo stanza. To resolve, remove orphaned/unused ports in the "Host Maintenance" section of your Admin module, then select "Compress port usage by reassigning higher ports into any available gaps" on the Admin page. For more detailed instructions, email

7. Proxy by port users: the proxy is not persisting through to the Credo database

Please check which version of EZ Proxy you have - versions prior to v6.1.12 may be unable to connect to Credo and are not supported by OCLC. If you're seeing this issue, please contact to discuss updating your proxy.

8. 400 Bad Request: Request Header or Cookie Too Large

This happens when a single EZ Proxy cookie collects the data for multiple databases. In the short-term you can clear your cookies; to fix the issue permanently, add "Option DomainCookieOnly" at the top of the Credo stanza in the Config.txt. It should replace the "Option Cookie" which is recommended in the standard config stanza. 

If you need any support for this process, please email, OCLC help at, or WAM proxy support at


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