Sometimes AutoCAD comes up with a notice noting “Do you really want to do this?” when moving hatches or something related to hatches.
This is most likely (in fact most of the time) related to associative hatches and their boundaries needing to be checked during a move, mirror etc. type command.
This does not always happen in all drawings with lots of hatch, in fact I only encounter it occaisionally these days. So AutoDesk is making hatch better, good for them.
A quick and dirty fix for this problem is to select all hatches and make them non-associative. Then everthing works as normal, well except the hatches don’t follow the outlines, but grip edit hatches make up for that!