Firefox gets critical error NS_ERROR_ILLEGAL_VALUE using OWA after installing SP3 UR7

Question

After installing SP3 UR7 Firefox shows an Exchange Error Message.
This occurs if using OWA by Firefox and opening the AutoReply or MailSettings Item.
It does not alway happen on the first run, but after clicking a second or third time to through the Items its always reproduceable.
OWA > ECP > E-Mail Organisation > Autoreply or Settings > Mail  (should be sth. like this because its a German Version)
NS_ERROR_ILLEGAL_VALUE:
Client Information
User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:32.0) Gecko/20100101 Firefox/32.0
CPU Class: undefined
Platform: Win32
System Language: undefined
User Language: de-DE
CookieEnabled: true
Exception Details
Date: Wed Oct 01 2014 17:20:40 GMT+0200
Message: NS_ERROR_ILLEGAL_VALUE:
Url: https://192.168.xxx.xxx/ecp/14.3.210.2/Scripts/editorstandalone.js
Line: 1
Call Stack
ErrorHandling.showUnhandledException@https://192.168.xxx.xxx/ecp/14.3.210.2/Scripts/common.js:253:1202
Function.createDelegate/<@https://192.168.xxx.xxx/ecp/14.3.210.2/Scripts/microsoftajax.js:5:298
Detailed Call Stack

Answer 1

Does FF have a debugging console that you can invoke when the error appears? Actually, it looks like it does:
https://developer.mozilla.org/en-US/docs/Tools/Web_Console
See if you can use it to find the exact function call that causes the error, and the parameter values.
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