I wanted to make this post so that maybe it could help someone out in the future. I noticed there were a lot of topics on this discussion with little to no resolve posted in their forum posting.

A quick overview of the system: PCS7 V9.1SP2, redundant server pairs, multiproject with clients which was all recent virtualized. This is a live running system in the facility and not a development system moving toward an upgrade.

There are some issues with how the systems configured, but we are currently in the process of correcting the issues. We had an interesting situation where an OS was restarted, not the thin client itself but the VM, and afterwards WinCC read "no connection to data server!". Ok, no big deal tried all of my normal checks like making sure file sharing was normal, Simatic Shell can see the servers, the client had physical network communication to the servers, running Reset_Wincc.vbs, re-downloading the client after another restart, and so on. None of which corrected the connections the client had with the server. We also had checked all of the services that should have been running while the runtime was up and none of them were running.

Since the client does not work anyway it was time for us to try some more invasive work. We started to think it was the server data files. We deleted the project (the entire project folder and recreated it and made sure sharing settings in groups were correct) off the client and re-downloaded the project. Still did not correct the issue. For a sanity check to make sure it was not the project we set the project to run on the ES. The runtime opened and was completely fine. This proved to us there was not a project issue, but definitely an issue with the clients communications to the servers. This is where we were running out of ideas and decided to....really start from "scratch". Basically we took the client out of the simatic manager multiproject and added it back in.

We ran Reset_Wincc.vbs on the client again, restarted the client, from the ES on the client we unassigned the OS from the client, re-assigned it (this breaks the simatic shell setup on the client which we wanted to rebuild communications), went through the steps of getting simatic shell setup on the client, and re-downloaded the client again. This fixed the communication issues, but our project was lacking some detail at this point. We had to add our custom @Logo pdl back into the project and then set the user rights back to normal. For some reason it kept the admin and super user rights, but not the normal operator level.

Closed because posted twice. The active topic can be found here:

PCS7 V9.1SP2 WinCC "no connection to data server!"

Kind regards, Moderator_Lan