Umbrella Intelligent Proxy SSL Decryption 516 Upstream Certificate CN Mismatch

[from_afar]

I started getting the dreaded 516 Upstream CN Mismatch error this afternoon for a few users. It is odd because on the page itself, there is no SSL error. Checking the certificate itself, the CN matches fine. I re-installed the Umbrella root CA just in case, but still get the error. 

The connection is "secure" according to the browser:

Found this help article https://support.umbrella.com/hc/en-us/articles/16794331853588-How-do-I-resolve-the-error-516-Upstrea... and the SAN matches as well:

I did turn intelligent proxy and ssl decryption off for a short while ~5 hours ago or so trying to diagnose a website issue, but other than that didn't make any changes. Am I missing something obvious here? I did re-download the root CA since re-enabling ssl decryption and imported it on the machine I'm testing on (and took the above screenshots from) and imported to the trusted root CA store, but I think the cert was the same. 

[Malwina]

It may be beneficial to reach out to Cisco Umbrella support, especially if you have already followed the article on the 516 error https://umbrella.cisco.com/support

[from_afar]

Thanks. Unfortunately, I'm leasing the system from AT&T which has been an absolute nightmare. As such, Cisco/Meraki just sends me their way and they have been abysmal when trying to get help hence I try to fix things myself first, then come here if I can't. 

At any rate, it fixed itself which is frustrating but at least it's fixed. 

Thanks for the reply.

[from_afar · Accepted solution]

The issue seems to have fixed itself once again which is super frustrating as I'd rather know what went wrong so I could fix it but the problem seems to be resolved.