Even if no error messages appear or any addon is shown in a lua error message it could be that an addon "hooked" into the ZOs code and breaks it.
if it's about leads and your last added addon was something that got to do with leads try to disable this particular addon and try if you are able to reproduce the error.
A good start always is to reproduce the error and write down the steps to any dev is able to reproduce it as well the same way+ fix it then.
If you are not able to use the mouse etc. anymore as the error happens try if pressing the return key at least starts the chat input and type /reloadui and press return. This way, having LibDebugLogger active, will clean your UI again and write the error message to the SavedVars.
Maybe another addon providing a reloadui global keyninding would help you as well. You define e.g. SHIFT+F12 (you need to install the addon EMACS or pChat in order to be able to use the SHIFT/CTRL/ALT keybindings!) to a reloadui and are able to reload the UI then if something happens like the total UI break down.
This addon should help here:
https://www.esoui.com/downloads/info...UIKeybind.html
It's outdated and discontinued thus not installable via Minion but it should work properly!