Clickin OK in new document dialog hangs the browser in IE11

1) Open the CMS and login
2) Go the the browse perspective
3) Click Hippo Duurzaam, Evenementen and Add new event...
4) Fill in a name
5) Click OK.
Expected: New document is opened
Actual: Ajax spinner keeps spinning in the dialog
On browser refresh the new document is opened. Second time the OK button works.
After logout/login the problem is reproducible again.