Hi @Bashir Ali   The official versions of macOS supported for FMRTE 20 are Mojave/Catalina, although it might work with previous versions.   In this case, in one of our last updates we had to made some changes, that made it incompatbile with macOS Sierra (10.12).   There is no fix for it, as it's not a bug. I would suggest you to update macOS to the latest version, or at least to macOS High Sierra (10.13)   Thanks