OK button disabled in new document dialog

When adding a new document, the OK button in the dialog is disabled / greyed out. Only after changing the selected document type a few times, does it become enabled.

• log in to CMS
• hit 'New document' in the top of the screen
• choose a document type in the dropdown (do not yet type in a name!)
• only then type in a name
• the OK button is greyed out

The OK button does get enabled if you switch to another application/window and back. Therefore taking a screenshot of this is impossible.......