Tim, my first suggestion would be to try updating to our latest minor release to see if this does the trick. If not, you may be able to manually up the user's quota in the JSON files so that you can get back into the domain and edit the quotas. You may want to submit a support ticket though as I don't think the quota should prevent you from accessing the admin account of the domain. 

This seems to occur regularly (however not every time) when using Edge.  Not sure why, but if I use Firefox, no issues.  

Thank you,

Tim