Try the windows search in your live/AddOns folder (or use an external free tool called "Notepad++:
https://github.com/notepad-plus-plus...rtable.x64.zip [Portable zip version, no installation needed! Just extract and run Notepad++.exe then)" and use it's menu Search -> "Search in files" [CTRL+SHIFT+F shortcut] -> filenames *.lua; *.xml files in the live/AddOns folder) and search for:
ExtendedJournalSearchFilter
Here is how it looks with Notepad++
Notepad++ is btw a very good editor, replacement for normal "Notepad" programm.
But if you feel you do not need it, you can also try the normal Windows search box in your file explorer, top right at the live/AddOns folder.
It might be faster to find the addon that uses or changes that virtual named control in your error message.