You don't say what operating system you're using.
But if you are using Windows 10, start up the program and hold down the Ctrl+Alt+Shift keys on the LEFT SIDE of your keyboard as the program launches. (On a Mac, hold down the left side Cmd+Opt+Shift.) You should get an indicator that the program is trying to change something on your computer. OK that and the program should finish loading.
I am using Windows 7, I just think it is strange that it has been working and then today nothing!!