Can other users open the migrated sites successfully? Or are it just farm-account and site-collection admins?
Does the service-account used for the application pool have db_owner permissions for the content database? On occasion I've seen SharePoint wanting to make some minor upgrades to the database schema upon first access of items and then failing if the ...
Please follow the upgrade instructions. The basic steps are:
On SharePoint Server 2013, use Convert-SPWebApplication to convert from Windows classic authentication to Windows claims (if using Windows authentication and if not previously done during a 2010 -> 2013 upgrade). This is a requirement prior to moving content databases to SharePoint Server 2016.
You may check the below troubleshooting approaches :
First try to check out the page then go for editing from home page.
Site Settings -> Site Content -> Site Pages ->then click on ellipses three dots "..." next to home page name -> Click on "..." -> Check out
Open the page directly in edit mode through the URL by just appending "? =edit" at end of ...