Ok, so this is what I've come up with.
Upon opening the zip with the DevClient in it, I noticed that there were two NPCClient folders, one labled "NPCClient_Ch1" and the other labled "NPCClient_House". I decided to use the the Ch1 folder (Not really sure if it matters)
I put all the package files from my MabiPro folder into the package folder from the NPCClient folder.
The first thing I attempted to do to launch into MabiPro was create a shortcut of ClientD.exe and put the parameters at the end of the target like so: C:\Users\USERNAME\Desktop\NPCClient_Ch1\ClientD.exe code:1622 logip:126.96.36.199 logport:11000 chatip:188.8.131.52 chatport:8002 setting:"file://data/features.xml=Regular, Japan"
I launched successfully into the client, but trying to connect to the server I got a "Server Cannot Be Reached" error
The second thing I decided to do was edit the start.bat file that was in the folder, although I'm pretty sure it does the exact same thing as the prior, and I received the same error when trying to log in.
It does not matter which one you use - they are exactly the same.
It sounds like your client version may be set incorrectly (out of date).
Make sure to remove all of the packages that were in the NpcClient by default, and only use packages that were distributed with the official MabiPro client.
I believe it comes with language.pack and data.pack - these both need removed.
Additionally, when you are launching this way, you do not receive updates from MabiPro's launcher.
Make sure the MabiPro client you are pulling packages from is fully updated.