Bob and the Sliding Doors is a lost educational Bob the Builder short that aired on PBS Kids airings of Seasons 1 and 2 of Bob the Builder. The short was divided into 2 parts, one at the beginning of the airing and the other at the end. Currently, a 2-minute clip of it is on YouTube featuring the 2nd half of the short, however, it is very low-quality since it was recorded with the camera pointed at the screen and there is lots of background noise. It can be viewed here: https://www.youtube.com/watch?v=NYFeHUFg4P0. The 1st half of the short is completely lost, except for the low-quality screenshot seen on the right of this page.
UPDATE 3/22/2021: the whole thing just got uploaded in good quality!