1.8rc1: UI hangs after doing block Mark Broken of 3 failed releasing servers

I had servers in Failed Released state. I then reattempted another Release after maas services had been restarted due to another issue which caused. 3 of the servers failed the re-release, I then block selected to mark them as broken. When I hit OK, the servers disappeared from the list but the OK CANCEL remained, and I couldn't click on anything. Everything is stuck/frozen.

Since the maas services were re-started prior to this, I did see an error flashed on one of my UI session which I did not get a chance to record but consistent with accessing the UI prior to all services being up. So, guessing that this has to do with UI session previously up that stayed up through a Restart of MAAS.

This is from java console script:

Consider using 'dppx' units, as in CSS 'dpi' means dots-per-CSS-inch, not dots-per-physical-inch, so does not correspond to the actual 'dpi' of a screen. In media query expression: (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi)
http://10.245.0.10/MAAS/static/fonts/ubuntu-r-webfont.woff2 Failed to load resource: the server responded with a status of 404 (Not Found)
http://10.245.0.10/MAAS/static/fonts/ubuntu-m-webfont.woff2 Failed to load resource: the server responded with a status of 404 (Not Found)
http://10.245.0.10/MAAS/static/fonts/ubuntu-l-webfont.woff2 Failed to load resource: the server responded with a status of 404 (Not Found)
10.245.0.10/:416 ('UNHANDLED', 'Unknown Error [maas-trusty-back-may22:pid=4522:cmd=PowerQuery:ask=ad49]')
http://10.245.0.10/MAAS/static/fonts/ubuntu-li-webfont.woff2 Failed to load resource: the server responded with a status of 404 (Not Found)
10.245.0.10/:416 ('UNHANDLED', 'Unknown Error [maas-trusty-back-may22:pid=4522:cmd=PowerQuery:ask=ad5e]')
10.245.0.10/:416 ('UNHANDLED', 'Unknown Error [maas-trusty-back-may22:pid=4522:cmd=PowerQuery:ask=accb]')
610.245.0.10/:165 WebSocket connection to 'ws://10.245.0.10:5240/MAAS/ws?csrftoken=3W4be2GxXxoSNuToxjhf7Jl9zNMxuIHi' failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED
210.245.0.10/:165 WebSocket connection to 'ws://10.245.0.10:5240/MAAS/ws?csrftoken=3W4be2GxXxoSNuToxjhf7Jl9zNMxuIHi' failed: Error during WebSocket handshake: Unexpected response code: 503
10.245.0.10/:7 TypeError: Cannot read property 'length' of undefined
    at u.$scope.allowShowMoreEvents (10.245.0.10/:5819)
    at Object.get (10.245.0.10/:8)
    at u.$digest (10.245.0.10/:7)
    at u.$apply (10.245.0.10/:7)
    at RegionConnection.onResponse (10.245.0.10/:304)
    at RegionConnection.onMessage (10.245.0.10/:288)
    at WebSocket.websocket.onmessage (10.245.0.10/:199)
10.245.0.10/:7 Error: [$interpolate:interr] Can't interpolate: {$ getInstallationData() $}
TypeError: Cannot read property 'length' of undefined
http://errors.angularjs.org/1.2.11/$interpolate/interr?p0=%7B%24%20getInsta…%7D&p1=TypeError%3A%20Cannot%20read%20property%20'length'%20of%20undefined
    at 10.245.0.10/:6
    at Object.m (10.245.0.10/:7)
    at u.$digest (10.245.0.10/:7)
    at u.$apply (10.245.0.10/:7)
    at RegionConnection.onResponse (10.245.0.10/:304)
    at RegionConnection.onMessage (10.245.0.10/:288)
    at WebSocket.websocket.onmessage (10.245.0.10/:199)
210.245.0.10/:7 TypeError: Cannot read property 'id' of undefined
    at updateErrors (10.245.0.10/:5059)
    at Object.updateSummary [as fn] (10.245.0.10/:5149)
    at u.$digest (10.245.0.10/:7)
    at u.$apply (10.245.0.10/:7)
    at RegionConnection.onResponse (10.245.0.10/:304)
    at RegionConnection.onMessage (10.245.0.10/:288)
    at WebSocket.websocket.onmessage (10.245.0.10/:199)
210.245.0.10/:7 TypeError: Cannot read property 'id' of undefined
    at updateErrors (10.245.0.10/:5059)
    at Object.updatePower [as fn] (10.245.0.10/:5105)
    at u.$digest (10.245.0.10/:7)
    at u.$apply (10.245.0.10/:7)
    at RegionConnection.onResponse (10.245.0.10/:304)
    at RegionConnection.onMessage (10.245.0.10/:288)
    at WebSocket.websocket.onmessage (10.245.0.10/:199)
10.245.0.10/:7 TypeError: Cannot read property 'id' of undefined
    at updateErrors (10.245.0.10/:5059)
    at Object.updateStorage [as fn] (10.245.0.10/:5180)
    at u.$digest (10.245.0.10/:7)
    at u.$apply (10.245.0.10/:7)
    at RegionConnection.onResponse (10.245.0.10/:304)
    at RegionConnection.onMessage (10.245.0.10/:288)
    at WebSocket.websocket.onmessage (10.245.0.10/:199)
410.245.0.10/:7 TypeError: Cannot read property 'length' of undefined
    at Object.updateMachineOutput [as fn] (10.245.0.10/:5207)
    at u.$digest (10.245.0.10/:7)
    at u.$apply (10.245.0.10/:7)
    at RegionConnection.onResponse (10.245.0.10/:304)
    at RegionConnection.onMessage (10.245.0.10/:288)
    at WebSocket.websocket.onmessage (10.245.0.10/:199)
10.245.0.10/:7 TypeError: Cannot read property 'length' of undefined
    at u.$scope.allowShowMoreEvents (10.245.0.10/:5819)
    at Object.get (10.245.0.10/:8)
    at u.$digest (10.245.0.10/:7)
    at u.$apply (10.245.0.10/:7)
    at RegionConnection.onResponse (10.245.0.10/:304)
    at RegionConnection.onMessage (10.245.0.10/:288)
    at WebSocket.websocket.onmessage (10.245.0.10/:199)
10.245.0.10/:7 Error: [$interpolate:interr] Can't interpolate: {$ getInstallationData() $}
TypeError: Cannot read property 'length' of undefined
http://errors.angularjs.org/1.2.11/$interpolate/interr?p0=%7B%24%20getInsta…%7D&p1=TypeError%3A%20Cannot%20read%20property%20'length'%20of%20undefined
    at 10.245.0.10/:6
    at Object.m (10.245.0.10/:7)
    at u.$digest (10.245.0.10/:7)
    at u.$apply (10.245.0.10/:7)
    at RegionConnection.onResponse (10.245.0.10/:304)
    at RegionConnection.onMessage (10.245.0.10/:288)
    at WebSocket.websocket.onmessage (10.245.0.10/:199)
1010.245.0.10/:7 RangeError: Maximum call stack size exceeded
    at Array.indexOf (native)
    at http://10.245.0.10/MAAS/combo/maas/?js/angular/maas.js&js/angular/factories…r/controllers/node_result.js&js/angular/controllers/node_events.js:1189:39
    at Array.forEach (native)
    at Object.E [as forEach] (http://10.245.0.10/MAAS/combo/angularjs/?angular.min.js&angular-route.min.js&angular-cookies.min.js:6:1020)
    at http://10.245.0.10/MAAS/combo/maas/?js/angular/maas.js&js/angular/factories…r/controllers/node_result.js&js/angular/controllers/node_events.js:1188:25
    at Array.forEach (native)
    at Object.E [as forEach] (http://10.245.0.10/MAAS/combo/angularjs/?angular.min.js&angular-route.min.js&angular-cookies.min.js:6:1020)
    at Object.getCurrentFilters (http://10.245.0.10/MAAS/combo/maas/?js/angular/maas.js&js/angular/factories…r/controllers/node_result.js&js/angular/controllers/node_events.js:1160:17)
    at u.$scope.updateFilters (http://10.245.0.10/MAAS/combo/maas/?js/angular/maas.js&js/angular/factories…r/controllers/node_result.js&js/angular/controllers/node_events.js:3799:41)
    at leaveViewSelected (http://10.245.0.10/MAAS/combo/maas/?js/angular/maas.js&js/angular/factories…r/controllers/node_result.js&js/angular/controllers/node_events.js:3646:24)

This javascript console output came from session that was up with RC1, then action were performed after upgrade to RC2 without reloading the page.