Very Large Number of Changes Appear in the Sync Change Log
Description: In mid-January 2017, a number of users reported seeing a very large number of changes they did not make in citations and sources appearing in their Sync Change Log window right before syncing, resulting in change logs that were many hundreds of pages long in some cases.
Cause: This issue is due to Ancestry maintenance work on their data collections. See the "Ancestry Comments" box below for details.
Remedy: Just this once it's OK to ignore the large numbers, especially if you have just made a full backup with media as is recommended each time you sync. Only the changes you have actually made will appear in your tree.