Just want to chime in here and say I had the same problem, and as I'm using it for free it was particularly infuriating since I didn't know what was going wrong and I wasn't able to re-try different inputs. Â I work at a university and it wouldn't be a big deal for my lab to subscribe me to the Pro service but I certainly can't do that as long as this doesn't work. Â I note though that if you reveal one step at a time, it will show most of the steps, but when you hit one near the end, then suddenly everything gets blacked out (I want to see those steps though!). Â My input to produce this was
y''(t) + a*y'(t) + b*y(t) = x(t)
NB, this equation did not have a problem:
y''(t) + a*y'(t) + y(t) = x(t)
The bug appears to arise where the pathways for solving these two equations diverge.