FLStudio using the latest release .
Reset your FLStudio settings .
Windows - If the User data folder is set to a location inside Program Files, Windows may prevent FLStudio access and so FLStudio will fail to start ...
FLStudio 20SystemToolsDiagnostics fldiagnostic.exe . Mac: Right-click the FLStudio icon and 'Show in finder'. Then right-click the FLStudio App and 'Show contents' then browse to: Contents > Resources > FL > System > Tools ...