**Where?** Commons.Wikimedia.org
**What problem?** Since today I can not use any tabs on Commons. I can see them, but clicking them does nothing. No problems on Wikipedia with using tabs. It occurs on file pages, user pages, also here in the Village Pump, but not while editing this message. There the Read and Show History tabs are accessible for opening by right clicking them.
**Last time the problem did not occur?** Yesterday
**My webbrowser?** Firefox 52.6.1 (64-bits) Long Term Service (LTS)
**My Opreating System?** Windows 7 (64-bits)
**Did I install new software or updates recently?** No
**Does the problem occur using a different webbrowser?** I tried Chromium and there the problem did not occur.
**Possible JavaScript error?** I looked at the Error Console in Firefox. There are some messages. I am pasting them:
- SDK worker-child started as frozen on unexpected initial document.readyState Object { initialDocumentReadyState: "uninitialized", windowLocation: "about:blank" } worker-child.js:62
- pixel.everesttech.net : server does not support RFC 5746, see CVE-2009-3555 (unknown)
- JQMIGRATE: Migrate is installed with logging active, version 3.0.1 load.php:139:615
- This page is using the deprecated ResourceLoader module "jquery.ui.position". load.php:57:291
- This page is using the deprecated ResourceLoader module "jquery.ui.widget". load.php:88:942
- This page is using the deprecated ResourceLoader module "jquery.ui.core". Please use OOUI instead. load.php:11:84
"Handler function threw an exception: TypeError: this.transport is null
Stack: send@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/main.js:1465:5
NEA_addSecurityInfo@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/webconsole.js:2217:5
NetworkResponseListener.prototype._getSecurityInfo<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/webconsole/network-monitor.js:488:5
exports.makeInfallible/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/ThreadSafeDevToolsUtils.js:101:14
NetworkResponseListener.prototype.onStartRequest@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/webconsole/network-monitor.js:429:5
Line: 1465, column: 5" ThreadSafeDevToolsUtils.js:80