Salesforce Obscura: Self-Registration in Communities
The Pain
You have a Salesforce Community (public-facing Digital Experience) that is protected by a login. You want to let people self-register. You are using either a VisualForce or Experience Builder page.
You are getting the dreaded “Your request cannot be processed at this time. The site administrator has been alerted.”
But you are not getting alerted. You are not getting any useful debug. You have scoured Stack Exchange and done literally everything anyone has ever written up.
The Diagnostics
You can enable the Configurable Self-Reg page and it works. But the VisualForce and Experience Builder pages won’t work.
The Thing That Fixed It For Us
Check your sharing settings. With Configurable Self-Reg, you specifically state which user you’re creating the new logins with (and it’s probably an admin, who probably has sufficient rights to see everything). With the other methods, you don’t have that option so it’s executing as the site guest user.
However, you probably are specifying which Account record to tie the new logins to. If your guest user can’t see any Account records (which, of course, it can’t by default post-Spring21), then you won’t get past the first hurdle for user creation, and you won’t get error emails.
Basically it’ll just die from an overage of protecting you from yourself. Set up a guest sharing rule to allow read-only to the Account that you’re tying new users to, and hey presto, hours of miserable thrashing resolved.
How We Got In This Mess In The First Place
We originally set up the Configurable Self-Reg with its custom controller, and modified said controller to do what we wanted it to. But you can’t add any text or guidance or, well, anything to the Configurable Self-Reg page, so insufficiently secure passwords or pre-existing user accounts throw obscure errors with no path to resolution.
The client found that unacceptable for some inexplicable reason.
So we adjusted the Experience Builder default “Registration” page and started getting the useless “request can’t be processed” message. Aaaaand we were off! on days of trying to figure out why we were in pointless-error-message hell.
Hopefully writing up our misery gives you one more thing to try that might just get you able to move on to new and better errors!