Client (who hosts our programs on their website) sends an email there is an issue! Resolve is asap. - I drop a brick if my boss finds out about this he will kick off.
I look into it the best I can but there is no testing environment for their website so do the best I can on our environment. Every thing seems to be doing exactly what it should and can't reproduce. So I email client I can't reproduce and everything looks fine are you sure it's not at your end?
They email back I got someone at our end to look at it and he's sure it's your end. So I spend a rather long time looking into this and still find nothing so email back for more information and a video of them reproducing the issue.
They email back: umm sorry seems it was our side that was causing the issue, only noticed it when making the video.

*sigh* more time wasted thanks clients!