When Page Diff feature is used, an error message shows for the old version.
we have gone through the forum and found the same issue has been addressed in 6.2 AEM 6.2 Versioning: Visual Diff feature between two versions is not working.
Please advice whether we have solution for this issue or we have to reach Abobe .
Steps to Reproduce :
touch UI console: select a page,
expand the timeline from left rail and select a version
then it will allow you to compare that version with the latest editing copy.