It's not quite as deadly as one might think--Embarrassing, Costly, Time consuming but not deadly.
In live theatre, something ALWAYS goes...well, maybe it's just not right. You could say that something went wrong but sometimes it isn't as bad as "wrong" more than it's not quite "right," or at least not what was expected.
When I direct kids, I always warn them, "Something will go wrong. Deal with it and KEEP GOING." One year, part of the scenery fell over. The kids picked it up, and picked up their lines and kept going. Another year, we had a cast member not show up, so the other kids divided her lines among them and kept going. At an outdoor performance, the scenery started blowing away and my 9 year old actress leaned over and caught it while she was saying her lines. It was brilliant.
So rather than not doing something because you might get it wrong, just take the blunder (apologize where needed) and keep going.
By the way, our Double Play Saturday for December is on the 17th not what was previously posted on Cwerks stuff.