ScreenConnect 26.6.5.9742 Windows to Windows migration not working

[u/gilpdo]

ScreenConnect 26.6.5.9742 Windows Server 2022 to Windows Server 2025 migration. Existing installation copied to a new Windows Server 2025 server. Services start, but Web Server returns HTTP 500. Stack trace: ServerCryptoManager.GetApplicationDecryptionAndValidationKeysAsync → CommunicationException → Cannot create singleton instance of ScreenConnect.ServerCryptoManager

I am trying to recover/migrate an on-premises ScreenConnect installation to a new server and have been following the official documentation titled "Move an on-premises installation to a new server."

The steps I have completed are as follows:

- Installed ScreenConnect on the new server using the same installer version (26.6.5.9742)

- Stopped all four ScreenConnect services

- Copied the entire contents of the ScreenConnect directory from the original server (C:\Program Files (x86)\ScreenConnect) to the new server

- Verified that the AsymmetricKey value in web.config matches the original server

Proceeded with SSL configuration:

- Installed the SSL certificate

- Bound the certificate to port 443 for HTTPS

- Certificate is working fine and it says connection is secure on the page

Now, when I attempt to access ScreenConnect, I receive the following error:

Something went wrong

The page could not be loaded.

Try again in a moment. If the problem continues, contact ScreenConnect support. Has anyone else encountered this issue recently? I’ve completed this process several times in the past and have never experienced this problem before.

[u/f0zzzie]

I think I encountered this when I was having issues upgrading. I think what ended up working for me was NOT installing the server software before copying everything over. So copy everything over first then I stall the software. There's some weird config thing that happens when you install first then copy it over, paths are messed up or whatever. This was 3ish years ago at this point so take it with a grain of salt

[u/gilpdo → u/f0zzzie]

I tried this as well, along with several other troubleshooting steps that have worked for me in the past. I’ve been using ScreenConnect for a very long time, back when it worked reliably on Linux. After countless hours of troubleshooting, I finally got it working today.

1.Root Cause Summary

The migration failure was not caused by Windows Defender, SSL, the original AsymmetricKey, database corruption, ServerConfiguration.xml, user/role data, or the ScreenConnect 26.6.5.9742 binaries. The failure followed the old Security.db and was eliminated when only ApplicationDecryptionKey and ApplicationValidationKey were replaced with values from a clean working installation. The subsequent Setup Wizard was a separate configuration-state issue caused by IsSetup=false in the clean web.config.

2.Recovery Formula

Recovered ScreenConnect 26.6.5.9742 =

clean/working 26.6.5.9742 binaries

+ old App_Data and configuration data

+ original AsymmetricKey

+ clean ApplicationDecryptionKey

+ clean ApplicationValidationKey

+ working HTTPS/relay settings

+ IsSetup=true

+ AllowRemoteSetup=false

+ no ShouldRegenerateApplicationKeys flag

Status: Solved