I have an elderly parent using an old mac OS (?catalina?)  that I remotely assist via Teamviewer.   Their HW is ancient so it won't run latest OS'.   Currently I cannot connect to their system and their migration status shows as "Outdated software".    I have confirmed they have internet access.  Trying to diagnose why I not longer can connect.    I can find no help on this status in TV documentation. 
Helpful insights:
-  What does this status mean?
-  Would this status prevent me from initiating a remote desktop session?
Thanks in advance.