If you're running MacOS, please note that Flux:: Center won't work when started directly from the .dmg image file. As displayed in the .dmg folder it requires to be installed in, and launched from, the MacOS Application folder.
To install Flux:: Center, simply open the .dmg image file, then drag the Center icon to Applications folder, following the purple arrow, then open it from the Application folder.
If you're running windows, please verify that you've installed the latest version of Flux:: Center, and if you still experience any problems, remove these:
If you yet still experience any problems after this, please try to uninstall Flux:: Center, and remove:
C:\Program Files\Flux\FluxCenter.app (the install folder),
then install Flux:: Center again.