Failure when trying to add a process plugin after "Static map"

There is a failure when I try to remove a single process plugin for a multi-property field:

TypeError: array_diff(): Argument #1 ($array) must be of type array, null given in array_diff() (line 627 of /Users/youri/Sites/drupal/modules/d8/wip/feeds8/feeds_migrate/src/MappingFieldFormBase.php).

Additionally, I discovered an issue when trying to remove process plugins for multiple properties at once. For this and for adding test coverage for the bug of above, I opened 🐛 Removing process plugins for multiple properties at once does not work Active .

MegaChriz → closed merge request !28

Tests are passing now! Merged.

Though I think I may accidentally have fixed the majority of this issue in 🐛 Removing process plugins for multiple properties at once does not work Active instead.

Automatically closed - issue fixed for 2 weeks with no activity.