I just changed the installation location of my stellaris to anther harddisk. And that warning popped out just won't let me reinstall the launcher.Anyway after hours I finally got the solution, just leave it here for anyone who might need it.
How to fix:
Go to:C:\Users\(YOUR USERNAME)\AppData\Local\Paradox Interactive,open launcherpath with editor(notepad,txt,visual studio code, whatever),just change the path to your new loaction. That is it.
How to fix:
Go to:C:\Users\(YOUR USERNAME)\AppData\Local\Paradox Interactive,open launcherpath with editor(notepad,txt,visual studio code, whatever),just change the path to your new loaction. That is it.