Hello there
chiming in with a similar problem.
Upgraded from 4.5.3 to 4.6.
it seems a custom post type I had created (‘artists’) and set to be a CPT-onomy for Woocommerce products is not recognised as such any more
<?php echo get_the_term_list( get_the_id() , 'artists', '<span class="tagged_as"> Artist: ', ', ', '</span>' ); ?>
throws an error now (due to the fact that ‘artists’ is not being recognised as a taxonomy, I believe).
Kind regards
Giacomo Bruzzo