Impersonate-- not loading (Account Console loading ...)

When attempting to ‘impersonate’ user in any of the realms – ‘Account Console loading …’ appears continously and no loading of the account. Example link below, in the perpetual loading state, is from the ‘Master’ realm. Any tips on where to look? Nothing incriminating appears in the ‘server.log’.

https://foobar.com/auth/realms/master/account/