running tests on my add-on: I pushed a new crafter using a piston into a coord that had a custom entity and received this message.
(This is unreleased add-on code, so I will share with staff in *private*, if necessary, to maintain custody and copyright. thanks in advance.)
[UI][warning]-UI Control: crafter_screen | UI Control: variables_button_mappings_and_controls | UI Control: safezone_screen_matrix | UI Control: inner_matrix | UI Control: safezone_screen_panel | UI Control: root_screen_panel | UI Control: root_panel | On Control Path: /crafter_screen/variables_button_mappings_and_controls/safezone_screen_matrix/inner_matrix/safezone_screen_panel/root_screen_panel/root_panel/redstone.crafter_label | Expected variable not found in ancestor tree: '$entity_test'
Nevermind: my UI interface had not considered the crafter when I wrote it. Please close - this is my issue - not yours - apologies