Page Comparison

Solution:

This condition is common when making a significant change (ie. to an early-numbered section) in the VPB.
While the system says 'Not Responding' it is actually working, and taking time to complete. If you wait, it will finish.

The delay is being caused as every section and item after the change must be renumbered after the deletion/move, which must happen immediately if the VPB has a status of Final.

The best process to avoid this delay is to work on a Draft Status book. When you do this, the renumbering does not occur (for any changes made) until you make the book Final, and 'Compile' all section/item numbering. Importantly the same delay does then occur, and you have to be patient to wait for it to complete.