Overlay does not disappear after leaving editor.

Steps:
1. Go to Content / Media library.
2. Drop a file.
3. Click Edit in Uploaded section from the pop-up.
4. Close the editor using the 'x' at the top.
5. Go back to Media folder.
Actual: Gray overlay stays, discovery bar menu is not loaded.
Expected: Overlay disappears, menu on the left is loaded.

Remarks: Problem occurs also when in step 4 some changes are applied and published.