Hi @larryb1, @drlstein,
Runtime exceptions when loading the application can cause issues like this.
Did any exception message pop-up when you try to open FxSound?
Can you try running FxSound as administrator?
To isolate the issue caused by any setting change, you can try renaming the folder FxSound under %APPDATA%. This will make FxSound to launch in factory default settings.
Can you provide us some information on your system configuration -
OS version, CPU, RAM and audio hardware.