Pronterface won't connect to my Anycubic Kossel Linear Plus For the Anycubic Kossel Linear Plus I have to upload data to the 3D printer from a software called Arduino and then close it. Then I open Pronterface and put in the right port and baud rate that is in the Arduino files and then click "connect". Afterwards it says 

connecting...


and that is all it does and doesn't fully connect to the printer. I've tried changing the baud rate and port in Pronterface, Arduino and the bit rate in the Device Manager but nothing works. 

Any suggestions on how to fix this?
I know this is coming very late, but I'll post anyway in hopes that it may help somebody else experiencing the same frustration.

I received all of the same suggestions again and again on the forums -- about baud rate, COM ports, and a lot else which failed to get Pronterface to connect.

At last I posted to the Anycubic User Group on FB, and quickly received what was in my case the solution -- and so ridiculously simple.

I was told to hit RESET two or three times on Pronterface after hitting CONNECT.  Yup, that did it!  

Good luck!!  :D