Maybe you can try playing the official server.
Private servers may not support the latest mods.
the game client loads past 1 intro screen then exits back to desktop
it often goes on sale for 1€ (?Steam?), used to have some events (?twitch and the likes) to get it for free even, but 1€ isnt bad for a moddable MMO :) If you play on a server other than NA/EU, you'll need an additional tool to get past the cheat detector. Look on Undercovertpervert's page with the other tools (I forgot the name of it). There is also a thread for modding for beginners. Use the search button (upper right looking glass) to help you get started. Modding BDO is daunting at first, but once you understand the folder structure, it becomes almost logical :p
There was also a post from undercovertpervert on his page explaining some of the symptoms. I think if you made it past the loading screen it means that you may not need the extra tool for the non EU/NA servers ? Private servers are all different from what I understand. Some allow you to mod the game by following their folder structure, so you'll have to use windows explorer to figure out what should go where, if there is a paz folder equivalent, a texture folder and a model folder, etc.
Alternatively, you could do a search for BDO private server and see in these forums if there are any that accept the mod and play there instead of your current one.
Have fun in your modding adventures :)