I thought you might be interested in looking at 1.56 Cannot continue with campaign due to incompatible version.
https://forums.bohemia.net/forums/topic/106605-156-cannot-continue-with-campaign-due-to-incompatible-version/?do=findComment&comment=1775342
× Pasted as rich text. Restore formatting
Only 75 emoji are allowed.
× Your link has been automatically embedded. Display as a link instead
× Your previous content has been restored. Clear editor
× You cannot paste images directly. Upload or insert images from URL.