In the issue Add content & config entity dependencies to views are added dependencies where Views should depend on all the things (config, modules, and content) that if they disappear would break the view but content dependencies *must* be optional. If a taxonomy term is deleted the view still maintains a reference to the term and when it calculates dependencies this fails with
Error: Call to a member function getConfigDependencyKey() on null in /usr/local/var/vhosts/unidesk.com/acquia/unidesk8/docroot/core/modules/taxonomy/src/Plugin/views/filter/TaxonomyIndexTid.php,
Why is this critical? This is affecting users upgrading to 8.1.0 because there is an update that re-saves all views - which recalculates dependencies.
Don't break if the term does not exist.
On affected sites where
views_post_update_field_formatter_dependencies there is a possible manual work around - you can edit the view and resave the taxonomy filter and then resave the view - this will fix the reference to the non-existent term and the update will proceed without failing.
It is not necessary to add a new post update since on affected sites
views_post_update_field_formatter_dependencies will not have completed and it will still show as an available update.
User interface changes
Data model changes