VMware View – Black Screen during login with Linux VM

The last couple of days I was playing around with a new View Pools based on Ubuntu Linux 18.04 VMs. After some initial test I created my working Image and made my pool for the users.
After a couple of days, I became a message from one of my users he could not login in the Linux Desktop. When he starts his Horizon Client he got a Black Screen and after a minute the connection was discard.
I started to investigate to the error and one of the first things I did was to looking in the Logfiles. First thing I did was to look into the installed packages which were different from my original Image. I noticed that the User installed Docker-CE in his virtual View Desktop to interact with a VMware Integrated Container (VIC) Server. For those which are not familiar with Docker, Docker need some devices (internal Network) to operate. This network is created during the installation. When I stopped the Docker Server and restart the viewagent the user could login again. After a reboot the login was not possible with the same Black Screen bevor. After these findings I looked at the logfiles from the viewagent-debug.log. There I found something in the Logs:

tail -f /var/log/vmware/viewagent-debug.log
018-08-28T18:50:53.911Z DEBUG [ComponentResponse] Reponse directed to:ID:/
2018-08-28T18:50:53.912Z DEBUG [ComponentResponse] Message is -4836c1bb:1654679ccbd:-1e95 cn=9175d3da-3be6-4353-8b36-9804624e402a,ou=servers,dc=vdi,dc=vmware,dc=int cn=linux-vms,ou=server groups,dc=vdi,dc=vmware,dc=int ubuntu-vdi-001 XXXXXXXX thisIsAframeworkSSLAlgo thisIsAframeworkThumbprint f7911431-339e-47d3-a36f-7c27ac8874c2 XXXXXXXX BLAST ready 22443 XXXXXXXX

In the Log I could see that the Blast protocol was mapped to the wrong (the Docker network). So that was the reason which the Screen keep Black when the user tried to login. After some searching how to find the Blast protocol to the right network I found the solution in the VMware Community (https://communities.vmware.com/thread/591320). In short the solution is: That you configure the correct network (Subnet)in the /etc/vmware/viewagent-custom.conf file and there the parameter "Subnet=XXX.XXX.XXX.XXX/24" . After that you must restart the viewagent service ( service vieagent restart ). That’s all and also after a reboot of a system the login is possible.
Hope this helps if somebody has the same problem.