Identify the MLFB (Part Number): Ensure 3RT841B is the complete number. Siemens part numbers usually look like 3RT1015-1BB41.

Right-click the setup.exe or install.inf file and choose "Run as administrator".

Once the process hits 100%, the TV will typically restart on its own. Remove the USB drive and allow the TV to boot up normally. When Flashing Doesn't Work: Hardware Failures

Which (e.g., Windows 11, Linux, macOS) are you installing it on?