I've been using Action! for years and for some reason this problem only just started happening recently.
Any time I try to change the Output folder for where my recorded videos save, the mouse cursor will pinwheel and stay like that forever; it will never open Windows Explorer so I can select a new folder, and I have to force close Action! after a while.
I have tried re-installing Action!, and I cleared the registry as well to reset all settings to default, but that didn't work unfortunately...