I'm trying to write a scene where two co-workers are trouble-shooting a new custom security or encryption routine. Someone else (who isn't present) wrote the code and he will have been careful to ensure it works before sending it to them. So maybe something in the implementation of it?

The scene is dual purpose, showing their interaction growing closer while also hiding something else in plain sight. The tech part of it can be whatever is plausible and easy to convey without bogging it down in details. I am so out of touch with that sort of thing I don't know what's plausible any more.

What could go wrong with uploading the new code into their office network or onto their phones which would need a bit of trouble-shooting? The kind of thing one person might overlook and another catch. Preferably with them being literally close while they do this. And again - easy to convey without bogging it down in details. Jargon is fine.

Edit: Turns out jargon is not fine. Well it would be in the sense I meant, but that's not how it was taken. Am overwhelmed by how much I can't understand well enough to follow here, let alone distill into a few phrases. I know the readers for my lakorn-novel are non-existent but I can't swamp them with details.

Edit 2: Sorry to have bothered everyone. I'm just going to trash this. It was a stupid idea in the first place. Thank you for your time.