TypeError with user manager

I am trying to use User Manager remotely over a satellite link to an RB750. I can log on to it remotely with Winbox fine.

I was able to use User Manager locally when on site. But when I try over the link I get the web page opening, three slashes come in the top left (i.e. loading) then this error in a popup. Could it be poor connectivity or something else?

The following client application error has occurred:


Cannot process ServerMessage (Phase 1)

Error Name: TypeError
Error Message: librariesElement is null

Please contact your server administrator.

which version of RouterOS do you use?