Try moving your UI_Soandso_server.ini file to the Desktop and logging in (for the character you are trying to log into). If that stops the crashing, if you could PM me your old ini file that would be great.
I have had this problem as well as of late, trying to log in and it failing / crashing after character select at a higher rate then succeeding. but it does let me in, just not every time.
I have a 4k monitor, and since the UI is hard to read at 4k, I play at 2560x1600. This requires me to close discord, open eqclient.ini and set windowed mode to true, log in, go to options and set to fullscreen, then open discord. otherwise it crashes at character select.