Yes, the problem is that I deleted all of the queues (that shouldn’t be possible right?)
Anyways, thanks to your hint I was able to add a new default queue using this query:
insert into egw_categories (cat_appname, cat_name, cat_description, cat_data, last_mod) values ('tracker', 'Default', 'Default', 'a:1:{s:4:"type";s:7:"tracker";}', 1728979104);