Unable to add teammates to developer workspace due to error

Hello!

Our team has a developer workspace and we are unable to add new teammates due to an error. 

Regardless of whether an inbox seat is assigned or not and which permissions are set, when trying to send invites to the new team member(s), an error message appears: “Cannot convert undefined or null to object”. We have tried different combinations of permissions and having an inbox seat, but the error persists. The invites are not sent and we are stuck on the “Set permissions” screen. 

We have also tried creating a new developer workspace and the same error occurs when trying to add the new teammate(s). 

There is a corresponding error log in the browser console: /ember/inbox/pricing_migration/migration_states/wmvkgtzf?app_id=wmvkgtzf:1 Failed to load resource: the server responded with a status of 404 ()

Any help or insights would be appreciated, thanks in advance!