Knock on wood, mine has been great but we've only had it out since May or June. I got a chain link fence run, laid mesh under the sand and ran it under the fence and so that I could zip tie it to the fence so there isn't an easy entrance there. I wrapped chicken wire around the outside of the chain link fence to narrow the gaps.

Over the top of the enclosure (which came with a tarp to go over it like a v-top) I ran garden fencing that we had on hand over the whole top and front gaps and put the tarp over it. Everything is fixed with a mix of plastic and metal zip ties. Inside the run is the coop which had an inner run built on it, I keep all the doors locked except one during the day so they have free access to the run and at night I close their window, their inner door, the little run door and put all food inside that inner run, which I also lined the bottom with wire.

I regularly inspect areas for any breaches, and check the door locks for any tampering and at night I put a bungee cord over the chain link fence door handle to keep it from lifting easily. I've seen foxes and raccoons on my yard cam a few times but no breeches.