Under rare circumstances, you may get "Unresolved" results: files that couldn't be categorized normally as Missing, Newer or Duplicate:
Unresolved items are those that have the same File Name, Date, but DIFFERENT SIZE, so we can't determine automatically what kind of files are them, because they don't are Missing, Newer or Duplicate.
Certainly are "Duplicates" by Name, exists in both sides and have the same date but different size. For example: a file "briefdescription.htm" in Source Folder, have the same date than file in Target Folder, but the size is different: 9,492 bytes for the first one, and 9,490 bytes for the second file.
You should review both files and choose what to do with any of them using the options on the pop up menu for each side.
If you want to keep those items Unresolved, just ignore results (usually is not recommended).
To manage those files, you have exactly the same functionality / options as described on Missing Files, Newer Files, Duplicates.