Are you on Windows or Linux?
If the patch involved replacing any of the padre binaries, it's best to make sure you only copy the correct binary for your OS.
Most of the time it should be ok, but if you're on Windows and copy padre-sw into your bin folder, and have a command that calls /bin/padre-sw (and not explicitly /bin/padre-sw.exe this could cause things to fail.
Other than that you can try to check the following:
On the page that returns the error try viewing the HTML source of the generated page. You might see a longer error message in the source code.
Try looking at the modern ui logs to see if there are any messages in the log tail. In recent versions there are two modern ui logs - the modernui.Public.log (for requests to the public http and https ports) and the modernui.Admin.log (for requests to the admin https port). Depending on the version the log file might be located with the collection level logs (from the collection's log viewer) or from the system logs (in the system menu of the admin UI).