TYPO3 Core

The issue occurs in 9.5.22 and 9.5.23

Steps to reproduce:
1. Open redirects module and add a new redirect
2. Open the link browser to set the target
3. Try to expand a nod in the page tree

I get the following error message in Firefox Inspector:
"The character encoding of the plain text document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the file needs to be declared in the transfer protocol or file needs to use a byte order mark as an encoding signature."

Chrome reports 404 Page not found.

The URL of the blank page doesn't work when it's url-encoded, but it works when decoded.