Problems with VNC und display driver

[Luckbert]

Hello,
My name is Jürgen and I try to adapt Openplotter for my needs.
Sorry for my English, I come from Deuschtland and must write everything with Google translator. 
I am running Openplotter OpenPlotter RPI v0.8.0 from May 23, 2016 on an RPI3
Connected is a
RTL-SDR Stick
WIFI dongle
Wireless keyboard
Monitor or HDMI

The installation and setup of Openplotter is done at home. On the boat, this display is installed.

Http://www.waveshare.com/wiki/10.1inch_H...n_settings

PROBLEM: If I install the drivers for this display, I can not reach the Pi via VNC.

Error message:
The port on which the computer is listening for a connection could not be contacted. 

Copy config.txt after driver installation

# For more options and information see
# http://www.raspberrypi.org/documentation/configuration/config-txt.md
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output

hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
dtparam=i2c_arm=on
#dtparam=i2s=on
dtparam=spi=on
enable_uart=1
# Uncomment this to enable the lirc-rpi module
#dtoverlay=lirc-rpi

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
dtparam=audio=on
display_rotate=0
hdmi_group=2
hdmi_mode=1
hdmi_mode=87
hdmi_cvt 1024 600 120 6 0 0 0
dtoverlay=ads7846,cs=1,penirq=25,penirq_pull=2,speed=50000,keep_vref_on=0,swapxy=0,pmax=255,xohms=150,xmin=200,xmax=3900,ymin=200,ymax=3900




How can I ran debug mode? 

I hope I can be helped. Thanks in advance.