Steps to Reproduce:
- go to https://commons.wikimedia.org/wiki/File:Banville_-_%C5%92uvres,_Le_Sang_de_la_coupe,_1890.djvu
- Click "Croptool" on the left side of the screen (you must have activated the croptool gadget)
- This (https://commons.wikimedia.org/wiki/File:Croptool_bug.png) screen appears for a very short time, and then you are redirected to a form about "What to crop?".
- When you enter the name of the file (File:Banville - Œuvres, Le Sang de la coupe, 1890.djvu) and click "open", nothing happens.
- Normally, you directly get the interface on which you select the part of the file you want to crop.
- I did the same steps a few weeks ago with the same file and computer configuration, and it worked.
- I did the same steps with other random files since the problem appeared, and it worked.
- After I posted it on commons's chat room, User:Yann tried the same steps and had the same problem.
- I am using the vector skin of commons, on Mozilla Firefox 60.6.0esr (32 bits), on a windows computer.