Hi @Till
Thanks for the info.
For some reason, your toolbars are not being added to the wysiwyg
JS object. Normally, an array of toolbars will exist at acf.fields.wysiwyg.toolbars
(this.toolbars
).
On line 115 of core/controllers/input.php
you will see:
acf.fields.wysiwyg.toolbars = <?php echo json_encode( $t ); ?>;
It is possible that this line of script is not being run due to a JS error on the page. Can you check for any JS errors?
Perhaps also do some PHP debugging to make sure line 115 is correct data?
Thanks
E