DVLS WebUI unavailable after upgrade to 2026.1.6.0
Hello everyone,
After updating from the latest version 2025.3.15.0 to 2026.1.6.0, I get the message “Server unavailable!” in the WebUI.
Everything worked fine with version 2025.3.15.0. With the current version 2026.1.6.0, the WebUI no longer works.
Everything looks fine in the Devolutions Console.
The scheduler has started correctly.
IIS is working.
.NET 10 Hosting has been installed.
The logs look fine.
According to the DPS.Console log, the update was successful.
Uninstalling .NET 9 (hosting and runtime) was also unsuccessful to get the WebUI functionally.
Reinstalling was also successful.
I would appreciate some help.
Many thanks in advance.
Alex
Recommended Answer
Hello all,
After further investigation, it turned out that the culprit in this case was a load balancer. As soon as we bypassed it, the connection worked properly, and there were no issues with the upgrade process.
Best regards,
Gerhard Ryznar
All Comments (5)
Hello Alex,
Do you receive a more detailed error message in your web browser?
Did you follow the upgrade procedure mentioned on the KB page?
Regards,
Min
Hello Min,
Thank you for your prompt reply.
No. I get a white screen with only the message “Server unavailable!” in the browser.
I followed the upgrade procedure. I've been doing it this way for years. We've been using the DVLS server for so long; it used to be called DPS (Devolutions Password Server). Since then, we've also migrated the server, etc., and there have never been any problems during upgrades.
Best regards,
Alex
Hello all,
After further investigation, it turned out that the culprit in this case was a load balancer. As soon as we bypassed it, the connection worked properly, and there were no issues with the upgrade process.
Best regards,
Gerhard Ryznar
Hello everyone,
Hello Gerhard,
Thank you again for your very quick response to my inquiry.
I checked the health check that caused the error. However, I cannot find any deviations in my configuration compared to the DVLS documentation.
https://docs.devolutions.net/server/kb/troubleshooting-articles/health-readiness-checks/
In version 2025.3.x.x, the Health Check https://fqdn/dvls/health (or /dvls/ready) redirects me to the login page. In version 2026.1.x.x, the same request returns a blank page.
I have temporarily set the Health Check to “TCP/443 availability.”
Is there a new way to check the health status of the server?
Many thanks in advance,
Alex
Hello Alex,
There was a small change for the URI between 2025.3 and 2026.1.
In fact, getting an empty page is the intended behaviour. Being redirected to the login page indicates an issue with the health URI.
For 2025.3 the URI for the health check would be https://fqdn/api/health starting with 2026 it changed to https://fqdn/health.
If the DVLS instance runs properly, you should see a Status 200 response in your browser:
(This reflects exactly the statement from the mentioned KB topic)
Please let us know if you have any further questions.
Best regards,
Gerhard Ryznar
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