I'm having the same issue with UD Mobile on two different ISY boxes, getting:
ERROR:Connection Type: oAuthPortal, Error coce 404
Also noticed that MobiLinc is not working.
I am able to log into both ISY boxes via the my.iso.io.
I'm able to go into the settings->system->{isy box} and then it connects and I can synchronize, however when I go to the main page I get the 404 error again.
Also the "test connection" works, but still get the error from main page.