Steps to reproduce the issue

1. Go to the media manager
2. Create a folder that ends in lots of dots ("testing.....")
3. Submit

Expected result

An error either in the modal, or the modal closes to display the error.

Actual result

The error displays behind the modal window and is not immediately visible.

System information (as much as possible)

4.2.6-dev

Additional comments

This could also have some better error handling.