After uprading from 4.10 to 4.11, the Media folder suddenly broke. It sits there with the loading graphic forever and throws this error in the console:

GET http://localhost/base/FolderBrowserService/GetChildren/-1?_=1354117524640 500 (Internal Server Error) DependencyHandler.axd:2
send DependencyHandler.axd:2
f.extend.ajax DependencyHandler.axd:2
f.(anonymous function) DependencyHandler.axd:2
f.extend.getJSON DependencyHandler.axd:2
Umbraco.Controls.FolderBrowser.Base.extend._getChildNodes DependencyHandler.axd:246
Umbraco.Controls.FolderBrowser.Base.extend.constructor DependencyHandler.axd:250
_class DependencyHandler.axd:6
(anonymous function) DependencyHandler.axd:251
e.extend.each DependencyHandler.axd:2
e.fn.e.each DependencyHandler.axd:2
$.fn.folderBrowser DependencyHandler.axd:251
(anonymous function) dashboard.aspx:287
o DependencyHandler.axd:2
p.fireWith DependencyHandler.axd:2
e.extend.ready DependencyHandler.axd:2
c.addEventListener.B DependencyHandler.axd:2

On top of it not displaying any media, I can't upload anything. I can add and delete folders, but that's all. I changed permissions to full control for the IIS_IUSRS thinking that it had to be a permissions thing, but that didn't fix it. Anyone have any clues?