Last night I was happily weaving away on a towel, though I knew I wasn't entirely focused on what I was doing. I removed the temple, advanced the warp, looked down at my weaving and wondered, "what is wrong with this picture." About 1.5 inches back the repeat didn't look right, so I adjusted the Ott light, looked again, and sure enough, I'd missed part of a repeat.
On occasions like this, there are weavers who would tell themselves this was an unexpected "design element." I am not one of them. This was a treadling error, and un-weaving was called for. I did not take a photo, but did remove the 1.5 inches and the towel was ready to weave on again. But not last night. I walked away. Weaving when you are feeling sleep deprived is not wise.