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Luke Osmundson 2Luke Osmundson 2 

MyDomain URL Critical Update Breaks all VisualForce pages?

When the new Critical Update is activated in our Sandbox organization, we get the following error on every non-managed visualforce page:

<DomainName>'s server IP address could not be found.

We left it overnight in case it was an issue with the DNS not being updated, but that doesn't seem to be the case. Deactivating the update restores all functionality. Does something else need to be updated in order to get our non-managed pages working?

Thank you.

Raj VakatiRaj Vakati
On March 16, 2019, Salesforce will remove instance names from Visualforce URLs for Salesforce orgs that have MyDomain deployed. We’re doing this to simplify the hostnames used in Visualforce URLs as well as eliminate the need to change them during instance refreshes and org migrations.

You can see examples of the before and after changes below:
Visualforce page with no namespace:
Old URL format: https://<MyDomain>--c.<instance><pagename (>
New URL format: https://<MyDomain> (
Visualforce page with a managed package namespace:
Old URL format: https://<MyDomain>--<PackageNamespace>.<instance><pagename (>
New URL format: https://<MyDomain>--<PackageNamespace><pagename (>
To help you prepare for this change, we have provided a Critical Update Console (CRUC) setting within the Spring ’18 release. The CRUC will let you test the new URL format in your production and sandbox orgs. For more information on the new CRUC setting, read the release notes.
Big EarsBig Ears
I'm getting a similar problem, but the error we're getting is: "Content cannot be displayed: org.apache.commons.httpclient.RedirectException: Maximum redirects (100) exceeded"

Did you manage to resolve this? I've done the suggested cache clearing and re-starting, but to no avail. Seems like an issue with the critical update itself...
Luke Osmundson 2Luke Osmundson 2
No, sorry to say we still haven't been able to resolve this critical update. 
Big EarsBig Ears
Luke - Thanks for letting us know - Have you been able to raise a case? We don't have developer support so we tend to get our cases closed without any assistance.
Elias PinheiroElias Pinheiro
Same issue here. I talked today with Salesforce support, i'm waiting for an answer.
Elias PinheiroElias Pinheiro
In my side was a proxy issue, we added the new domains to the white list and now it's everything working.
Big EarsBig Ears
@Elias - Thank you for the response. Where did you whitelist the domains? And which domains were you whitelisting?