Tools becoming disabled?

Storyboard pro keeps deciding to disable its tools.
I dont know if that’s what it’s called, but basically the mouse icon is a crossed-out circle for the brush, select tool, erase, everything. No other functions are damaged, though. I think it’s happening after I use the timeline?
I’m not sure what’s causing it, or if I’m just missing something, but I have to quit and reopen the program each time.
If anybody can help, thank you, I’m pretty new to this program.