I asked Aria to explain some regex I was using. Aria closed the side window, and when I open it back up it shows the following. A restart makes no difference and there doesn't appear to be any way to recover from this.
Error: Unknown language: `regex` is not registered
at t (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:180184)
at Object.CI [as highlight] (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:180370)
at chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:291138
at chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:74467
at node (element<code>) (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:74095)
at node (element<pre>) (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:74252)
at node (root) (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:74252)
at DA (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:74330)
at MA (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:74416)
at chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:290535
at chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:13833
at a (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:14021)
at r (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:13980)
at a (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:14005)
at chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:13945
at a (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:14021)
at Object.run (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:14042)
at a (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:15851)
at o.run (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:15916)
at o.runSync (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:15968)
at ew (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:172:110865)
at Oo (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:2:328063)
at Ol (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:2:384891)
at yc (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:2:374043)
at Ec (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:2:373971)
at bc (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:2:373834)
at sc (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:2:370641)
at oc (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:2:369196)
at C (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:2:441278)
at MessagePort.x (chrome-extension://igpdmclhhlcpoindmhkhillbfhdgoegm/aria.js:2:441810)