Comment 2 for bug 1544888

I have the same issue in a multi-domain environment.

In my case regular users are in the default domain and the admin user is in the 'admin' domain. Trying to edit a project via horizon does not work e.g. Identity-> Projects-> Edit Project.

When trying to do so, I get the following error -> "Error: Unable to retrieve volume limit information."

When trying to save a project I get the following error -> "Error: Modified project information and members, but unable to modify project quotas."

In the cinder logs I see the same error as noted in the initial bug report -> "Caught error: Non-default domain is not supported"

The workaround in comment #1 does not work for me.