When a filename contents % and we try to download the file using the admin interface, its throwns an error: The filename fallback cannot contain the "%" character.

Steps to reproduce:

Install clean version of DXP

Create a content object file and attach inside this content a pdf file with % in its filename and publish

After publishing, you are redirected to the content view.
Try to download the pdf file using the download button

You will observe an exception

Other way to test: lets say the file name is : new file

if you try to downlaod it via admin/content/download/63/file/new-file you will get the exception

Using the router : ibexa_content_download =>/content/download/{contentId}/{fieldIdentifier}/{filename}

Expected result:

No exception should be thrown. We can remove % character from filename.