OK - I'll throw one out there and see what comes back….
The project was to capture a short sequence of an engineer entering a data centre, diagnosing a network problem, fix it, check it's fixed and then leave.
Since the data centre had around 1000 computers running in the racks, with all the associated fans running, not to mention the data centre air conditioners, we couldn't capture any useful sound on the day, so all sound was added in post, recording what ever we didn't already have.
We also had to replace the screen on the diagnostics tool in all shots because their tool didn't have any usable graphics etc.
The client wanted a blue-hue and a sci-fi drone noise, just in case you were wondering….