Why so many crashes?

With all the buzz lately about the disclosure of retrieved crafts, I’ve been pondering a cosmic conundrum. If these crafts are indeed from civilizations with technology far superior to ours, what could possibly cause them to crash? It’s a bit like seeing a supercomputer tripped up by a simple math problem, isn’t it? I mean, we’re talking about engineering that’s light years ahead of us, right? So, what’s the deal? Could it be our planet’s magnetic field playing tricks on their navigation systems? Or maybe they’re just not used to our Earthly weather conditions? I’m all ears for your theories.