At an old job, there was a client who was needing help fixing some fancy software/hardware that my company supported. It was apparently a somewhat dire situation so they needed someone to fly out urgently to fix it, or something like that, I wasn't a part of the initial nothing-put-into-writing call. (Miscommunication 1)

My co-worker at a different office bailed at the very last minute and said someone else would need to do it. I drew the short straw so I was basically flying out in an hour or so to see this client that I've never met and had no experience with.

I asked said co-worker for details on the client, to which I got a somewhat snobby reply of 'well this is what the [CRM] is for, dummy'. (This was miscommunication 2)

So alright cool grab the client name, hand it over to the secretary who sets up flights and other arrangements, and I'm off in a rush. (Miscommunication 3)

Secretary got [Client], LLC and not [Client], INC. Neither of us realized there were two of the same names in the system.

I arrive at the client's site, walk in, and they are completely baffled on why I am there and what I am trying to do. After a ridiculously embarrassing call with my boss I ended up driving to the correct location, several hours away, and showing up early in the morning.

...Only to find out that the client was ultimately missing a license key. One that they didn't have nor did we have, but a separate third party who originally set it up. We didn't know that was the case because my co-worker was the only one who had experience with this client and didn't mention this. (Miscommunication 4)

It was a miserable time.