I'm happy enough with the 2 prefabs we inherited from other chicken owners who gave up. What made them work was installing them inside a huge walk-in chicken run my beloved son built for me. The doors of the coops can stay open except when we're using one coop as a brooder for babies. With small trees and bushes inside the run it's second best to free ranging but totally safe for them.I didn't expect so many replies.
I'll share my mistake.
1.What did you do?
when I first started chicken keeping, I didn't know about how bad prefabs are (and how addicted I'd get to chickens/ how many I'd get) and I bought one.
2.What were the consequences?
Luckily, it's really big but I still can't have as many chickens as I want. I dream of a huge walk-in coop.
3.Did you fix it? How?
I couldn't fix it, it would be a waste of money and I can't afford a larger coop. I'm lucky that all my chickens are okay and fit in well.
4.What did you learn?
Don't get prefabs, especially if you are planning to have a multiple generation flock

I had failed to protect my babies and they relied on me to keep them safe. Now I have three alarms set for bed time to lock them in safely. The three alarms are if I miss the first or second one I at least get one of them which guarantees them safely being put away. I love them all so much, to lose any others in this way would just be too terrible to bear...
sorry to hear of your loss.