At work, I was given the responsibility of "updating" a near ancient player so we can use it with more modern equipement. In other words, connect it to a PC (or some other suitable modern recorder), so I can convert from the old medium to a more modern medium so someone 50 years down the road can have the same problem of converting from the current medium to whatever medium they're using.
So I set about the task of figuring out why it isn't working and I conclude it's a drive belt. The original was made from cloth and I suspect some kind of rubber compound long rotted away. The powers that be, the guy mastering the project, elects to have someone else construct a new belt from, what else, cloth. Meh, I was just going to scrounge through the VCR belt collection to see if that worked.
M'Kay, whatever, as long as it works, I don't care what the belt is made from.
Today, they pull me from my office and have me take a look. "The machine still isn't working!" They say. They've been fussing with the machine for nearly an hour. Pieces of paper jammed into one of the DPDT leaf switches. They tell me it needs to be this way because they feel it's a deadman's switch (it's not).

After about five minutes fiddling with the switches and reseting them to their proper positions, I decide the real problem lay in the fabricated belt. Just not enough tension.
So I spend the next thirty minutes trying to explain to my co-worker in the nicest way possible, the belt just isn't tight enough.
They tell me, "the deadman's switch needs to have paper in it to work." I explain several times, that no, it's not supposed to be that way.
They tell me, "one of the cords has a short." I explain that if the belt isn't turning, then we don't know if the cord has a short.
Then it's (another) wheel not engaging. It needs to have media. The player needs to be reset.

No, no, and no. Check the belt guys. It's the belt. The belt!

They finally decide to check the belt. The machine, more or less, works.

So who gets credit? Not me.

Oh well. I get my machine back in a few days and I do what I originally needed to do... adapt it.
I never really understood this part of human nature. Something goes awry and when a lower echelon points out the error, the other refuses to admit or accept the mere possibility of the mistake. It doesn't matter how nice, subtle, or blatant I am about it. People simply refuse to acknowledge and when they finally figure it out (sometimes days later), they get credit for the solution.

It was always like that at every job. I would
like to get credit for solutions, but at the very least I would like the other person to admit the mistake so I don't blow days or weeks of my time while they dick around with my machinery.