CircuitLab plugin doesn't load for me in latest Firefox

Out of curiousity I clicked on the circuitlab (Ctrl-M) in a post to play with it, but it doesn't work for me. (Up to date Firefox, 20.0.1)

When I click it my screen flashes white for a second with a black border, and I get a small box in the center which says "Loading Editor".

After about a half second, the white screen/black border dissappears, and I'm back on the question page. The "Loading Editor" dialog is now superimposed over the original question page, but it never disappears, just keeps animating the loading ellipsis forever, until I press cancel or leave the page.

If I go directly to circuitlab.com, then the editor loads fine and I can play with it.

If it's of any help, this is what my firefox dev console says right after I click the circuitlab button:

[16:00:45.411] Error in parsing value for 'left'.  Declaration dropped. @ http://electronics.stackexchange.com/questions/66322/
[16:00:45.486] GET http://electronics.stackexchange.com/plugins/schematics/editor [HTTP/1.1 302 Found 180ms]
[16:00:45.680] GET https://www.circuitlab.com/editor/editor_embed/StackExchange/ [HTTP/1.1 302 Found 134ms]
[16:00:45.820] GET https://www.circuitlab.com/editor/#?editor_embed=true&editor_embed_username=StackExchange [HTTP/1.1 200 OK 52ms]
[16:00:45.871] Unknown property '-moz-box-shadow'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:558
[16:00:45.871] Unknown property '-moz-border-radius'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:559
[16:00:45.871] Unknown property '-moz-background-clip'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:560
[16:00:45.871] Expected declaration but found '*'.  Skipped to next declaration. @ https://www.circuitlab.com/assets/css/public-1365560489.css:561
[16:00:45.871] Error in parsing value for 'background-image'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:573
[16:00:45.871] Expected color but found 'top'.  Error in parsing value for 'background-image'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:573
[16:00:45.871] Error in parsing value for 'filter'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:573
[16:00:45.871] Unknown property 'box-sizing'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:574
[16:00:45.871] Unknown property '-moz-background-size'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:575
[16:00:45.872] Error in parsing value for 'line-height'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:639
[16:00:45.873] Error in parsing value for 'font-size'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:772
[16:00:45.873] Error in parsing value for 'font-weight'.  Declaration dropped. @ https://www.circuitlab.com/assets/css/public-1365560489.css:772
[16:00:45.876] Expected ':' but found '0.9em'.  Declaration dropped. @ https://www.circuitlab.com/assets/editor/SimGuiStyle-1366448146.css:92
[16:00:45.876] Expected color but found 'none'.  Error in parsing value for 'background-color'.  Declaration dropped. @ https://www.circuitlab.com/assets/editor/SimGuiStyle-1366448146.css:249
[16:00:47.072] GET https://www.circuitlab.com/i18n/jsi18n/?lang=en&v=1366448146 [HTTP/1.1 200 OK 45ms]
[16:00:46.038] Unknown property 'box-sizing'.  Declaration dropped. @ https://www.circuitlab.com/editor/#?editor_embed=true&editor_embed_username=StackExchange
[16:00:47.154] GET https://d2dq2ahtl5zl1z.cloudfront.net/analytics.js/v1/v3bq9ioc53/analytics.min.js [0ms]
[16:00:47.154] GET https://twimgs.com/shared/omniture/h_s_code_remote.js?_=1366498845994 [0ms]

• Are you running any kind of script blocker? From the log you posted, I don't immediately see why it doesn't work. Apr 21 '13 at 4:07
• It didn't load immediately with NoScript on, but allowing circuitlab.com worked for me in Firefox.
– W5VO
Apr 21 '13 at 5:07
• I am running FF 20.0.1 on Win7/64 and the circuitlab thingy seem to work. Apr 21 '13 at 7:13
• I'm on XP, FF 20.0.1, and it doesn't work for me, even after disabling all add-ons and allowing circuitlab.com. It doesn't work for me in Chrome 26.0.1410.64 m, Opera 12.15 and Safari 5.1.7 either, whilst it first did work in all these browsers. I downgraded to FF 18.0.2, the problem persists.
– user17592
Apr 21 '13 at 7:21
• new java engine? Is it a java application or javascript? I believe javascript comes with the browser, whereas java is a separate package. Apr 21 '13 at 7:29
• I don't have noscript (do have adblock, but it's globally disabled when this reproduced). Also running win7-64. Java version on my pc is 1.7.0_01.
– Tim
Apr 21 '13 at 8:04
• I also just updated my java plugin from SE7-U15 to SE7-U21 (the latest) and it didn't help.
– Tim
Apr 21 '13 at 8:18
• Tim, do you have the same problem in other browsers?
– user17592
Apr 21 '13 at 9:48
• I don't really use other browsers, but I just checked some old chrome install (have no idea how old it is), and I got the same non-working behavior.
– Tim
Apr 21 '13 at 17:26
• Thanks for bringing this to our attention. We're currently investigating what changed that could have caused this. Thanks!
– weiy
Apr 23 '13 at 17:48