First thing to do is to try and reboot into safe mode and see if that makes a difference.
Also, were you running a script via user scripts set to run at Array Start. Previous versions of US if the script didn't exit would stop the UI from loading until the script actually finished (this was by design, but was changed on today's update).
If this is what your issue is, then what you're going to want to do is edit /config/disk.cfg on the flash drive and change startArray="yes" to be startArray="no"
Then reboot and go to user scripts / plugins and update the plugins
Then try starting the array. If that works, under disk settings you can change the setting back to auto start the array.