Problem
Open a .snagarchive file in Snagit 2022
Solution
Install Snagit 2021 using this link
Open Snagit 2021 Editor: Edit > Editor Preferences > Library tab > Backup/Restore Automatically Stored Files.
Once the files are restored correctly in Snagit 2021 fully close out of Snagit 2021 and then open Snagit 2022 and in the Editor go to Library and Convert Captures Now 
Video walking through this process:
