It is just an anomaly that occurs from time to time, where there is a newly created column with a zero or X at the end of the chart which cant be placed into a new column (yet).
The VBA keeps looping trying to place it somewhere, but there is no where for it to go.
So when I hit escape it stops looping and leaves it like this - below - which is correct.
see the image below, where it can't place the last X
