Problem with update from 12.3.2.5

[S_Kunimuench]

Hello everyone,

I'm currently still on version 12.3.2.5. With this version, I set up a second scan server, which is working very well.

However, I’m unable to update to a newer version, and I'm not sure if this issue started after setting up the second scan server.
Every time I try to update, it proceeds up to the start of the update, and then a browser window opens with the unhelpful message:
"An Installation Error Occurred. It looks like something went wrong."

Does anyone have an idea what might be causing this? These are the last lines in the setup log

2025-05-12 07:33:53.256   Extracting temporary file: C:\Users\xxxxx\AppData\Local\Temp\is-R3TN2.tmp\WebpiCmd-x64.exe
2025-05-12 07:33:53.256   Extracting temporary file: C:\Users\xxxxx\AppData\Local\Temp\is-R3TN2.tmp\WebpiCmd-x64.exe.config
2025-05-12 07:33:53.271   Extracting temporary file: C:\Users\xxxxx\AppData\Local\Temp\is-R3TN2.tmp\Microsoft.Web.PlatformInstaller.dll
2025-05-12 07:33:53.319   .Net Framework 4.8 already installed (4.8.04161).
2025-05-12 07:33:53.319   Extracting temporary file: C:\Users\xxxxx\AppData\Local\Temp\is-R3TN2.tmp\VC_redist.x64.exe
2025-05-12 07:33:53.319   CurStepChanged raised an exception (fatal).
2025-05-12 07:33:53.319   Deinitializing Setup.
2025-05-12 07:33:53.319   Lansweeper Setup Aborted! Failed Actions: Error:  The process cannot access the file because it is being used by another process.! Failed:  The process cannot access the file because it is being used by another process.! Errorcode: 
2025-05-12 07:33:56.422   Failed to remove temporary directory: C:\Users\xxxxx\AppData\Local\Temp\is-R3TN2.tmp
2025-05-12 07:33:56.434   Log closed.

I’ve already stopped and disabled all Lansweeper services and rebooted the server, but the same behavior persists.

I’m using Lansweeper with IIS (not Express) and a separate MS SQL Server.

Thanks and best regards,
Sascha

[S_Kunimuench]

Hello Frank,

I've already done that. I stopped and disabled all services to ensure they wouldn't restart after a reboot. Unfortunately, the same error still occurs.
This happens on both servers — the main server and the scan server.

Best regards,
Sascha