Errors in the console

[iDrugoy]

Error: [Exception... "'JavaScript component does not have a method named: "getHelperForLanguage"' when calling method: [nsIClassInfo::getHelperForLanguage]" nsresult: "0x80570030 (NS_ERROR_XPC_JSOBJECT_HAS_NO_FUNCTION_NAMED)" location: "JS frame :: jar:file:///C:/path2firefox/profile/extensions/%7B73a6fe31-595d-460b-a920-fcc0f8843232%7D.xpi!/components/noscriptService.js :: <TOP_LEVEL> :: line 1347" data: no]
Source File: jar:file:///C:/path2firefox/profile/extensions/%7B73a6fe31-595d-460b-a920-fcc0f8843232%7D.xpi!/components/noscriptService.js
Line: 1347

Error: [Exception... "'JavaScript component does not have a method named: "getInterfaces"' when calling method: [nsIClassInfo::getInterfaces]" nsresult: "0x80570030 (NS_ERROR_XPC_JSOBJECT_HAS_NO_FUNCTION_NAMED)" location: "JS frame :: jar:file:///C:/path2firefox/profile/extensions/%7B73a6fe31-595d-460b-a920-fcc0f8843232%7D.xpi!/components/noscriptService.js :: <TOP_LEVEL> :: line 1347" data: no]
Source File: jar:file:///C:/path2firefox/profile/extensions/%7B73a6fe31-595d-460b-a920-fcc0f8843232%7D.xpi!/components/noscriptService.js
Line: 1347

[Giorgio Maone]

Really strange, there's nothing at line 1347 which could trigger this error unless it is caused by something JS wrapping the channel.
Does it happen also on a clean profile with just NoScript installed?
If not, please use Standard Diagnostic to find the very likely interfering extension.

[maxmaster]

For me it is happening while trying to install any userscript from http://www.userscript.org while Greasemonkey is installed.
No idea which addon is at fault here as the error only pops up when both addons are active.
Confirmed with a new profile and only those two addons installed, no allowing of any sites needed.