The theme preprocess hook for entity_add_list on this module is too generic and applies to all entities.
By example, the add media page links are all rewritten with assignment entity type which leads to faulty link (404).
Exemple project: TG. Go to Media section of the content administration. Click on add Media, then try to select one media bundle.
I was not able to identify the reason behind this preprocess, as on TG there is no 'Add assignment' page. So first resolution would be to check if this hook is really necessary. If not remove it, else we should then check if the provided bundles are matching the entity type assignment. See MR.
Fixed
3.0
Code
Automatically closed - issue fixed for 2 weeks with no activity.