On all page views in IE 11, the following error is logged to the console:
Exception in store-eval:
SyntaxError: Expected ';'
I can reproduce this in BrowserStack using Windows 8.1 and IE 11 on mediawiki.org, en.wikipedia.org and localhost (MediaWiki-Vagrant).
Narrowing it down I find the following:
- It only happens when loading code from localStorage. When running localStorage.clear() the first page view is fine.
- It comes from the "jquery.uls.data" module. (Patches mw.loader#asyncEval to run globalEval in a for-loop and log the first part of each string.)
This means that in IE 11, users are stuck in the following loop:
- First view loads JS from load.php and populates localStorage.
- Second view loads modules from localStorage, until ULS is reached in the list of modules. Error is caught. localStorage is cleared. Rest of the modules are loaded from load.php.
- Third page is as the first view.
- Fourth page is as the second view, etc.