Need help transitioning from axis XYZ to XYYZ

Hello, 

I dont know, if i am in the right folder, but it seemed like the right one. If not, just move the topic.I have already now managed to get my ethercat servos and i/o running, with 3 motors for XYZ. Now that i have everything running, i want to finally add my second motor on the Y axis for my Gantry setup. Connecting the joints with the ethercat is no problem. But if I go in the ini, add joint_3, set the joints =4 and rewrite the coordinates = X Y Z to = X Y Y Z, and start the machine, i get an error, that my joint_3 min and max limits does not match with the min and max limits on the Axis A. but i dont have an A Axis set up. I guess it wants to merge the Joint_3 with the A Axis, but thats not set up. As far as I understand,  with XYZ it is mapped the following: Joint_0=X Joint_1=Y Joint_2 =Z. Then when i go with XYYZ it should be the following: Joint_0=X Joint_1=Y Joint_2=Y Joint_3=Z. But somehow it is: Joint_0=X Joint_1=Y Joint_2=Z Joint_3=A? Is there somewhere else except the .ini where i need to join the Joints with the axis? what else do i need to change/set up? I started with the sim Axis mm. If i need to post any files, tell me.
I also managed to crash my PC, when starting LCNC. After double clicking the icon, nothing happened, and after like 30s the whole PC froze. After digging around in my changes, i saw that i wanted to change the number of joint from 3 to 4, but forgot to put 4. so it was accidentally left blank, like this: Joints =  
If that helps anyone, here you go.

Thanks