[German]I received a reader report complaining about problems with Remote Desktop Server. Various customers are experiencing freezing issues with virtualized Windows Server instances. The strange thing is that this effect occurs at a specific time of day. It could be, or is likely to be, due to Trend Micro. After I posted the German edition of this blog post, I got several confirmations.
German blog reader Robert H. works as an IT employee and supports various customers who use Windows Server. In the course of his work, he encountered a problem and asked to address it here in the blog.
The Windows Server environments
Various customers of the reader use virtual Windows Server versions (2019, 2022, and 2025). The Remote Desktop Server role is installed on all Windows Server instances. These servers are either standalone or part of an RDS farm, some with user profile disks (UPDs) or local user profiles, the reader wrote.
Remote Desktop Server Freezes
For unexplained reasons, the Windows Server instances sometimes freeze at the same time (around 2 p.m. CET) on the same day. This manifests itself in such a way that all active sessions on the server remain intact. However, the user sees a black background on the RDP connection.
It is no longer possible to log in to the Windows Server via Remote Desktop. The only solution is to restart the Windows Server. After that, normal operation is possible again—until the next freeze. The problem for the reader: No events are logged at the time of the freeze.
Could Trend Micro be the cause?
The blog reader wrote that Trend Micro Worry-Free Business Security (WFBS) is installed on all affected servers. After suspecting that the product might be the cause, IT uninstalled Trend Micro from the affected machines.
Since then, remote desktop connections on the Windows servers have been running without freezing. It can therefore be concluded that the freezes were caused by Trend Micro Worry-Free Business Security (WFBS).
I asked Robert's question: "Are there any similar known problems among the readership?" within my German blog a couple of hours ago. Since then I got a couple of confirmation.
Addendum: I got a report, that Trend Micro provided a fix, see Remote Desktop Server: Does Trend Micro version 6.7.4065/14.3.1342 fix the freezes?
Did you ever find out what Trend Micro feature or module might've induced the freezes?
We are having this exact same problems on multiple RDS Collections and we are also using Trend Micro WFBS.
We've even created a new collection from scratch in hopes of mitigating these issues. So far, these new servers/collection have yet to freeze, but they are also using TM, which is why I'm curious.
If removing TM really did fix these issues for you, we might go with another AV solution.
Till now my German blog readers don't geht a final solution – except uninstalling TM.