Crash to Desktop/Server on every Zone or Most Zones.
The UserData folder is holding a series of journalled entries.
In most cases, a corruption has been introduced that is causing the Crash On Zone. Seems that these files are read when you zone.
1) Navigate to the Everquest Folder and locate the UserData folder.
2) Delete the contents of this folder.
3) When you log back into EQ, do an ALT-J and uncheck the Journal Logging feature.
4) Should be good to go from then on out.