I got exactly the same error for no reason.
Was running everything perfect and suddenly got crashed and could'nt login again.
I've tried:
- update files;
- deleted Maps/21_18.unr and Textures/T_21_18.utx;
- Now, I deleted Maps and Textures and Im updating;
Funny is, I copied same L2 folder to a HD and tried on my notebook and work perfectly.
Plz @Koll, help me back to my vicious routine.