umm I see. When Arianna's breeding script was integrated into Mys v1.2.0, it automatically created a lv.0 entry in table prefix_levels. Because of this, we had to get rid of one of the lv.0 rows or it would end up looking like this from Mys v1.2.0 beta:
So yeah, we fixed this glitch in the official release of Mys v1.2.0. However, it seems that the url linking to adoptables deletion page is missing from here. The adoptables deletion script is still available, its just not directly accessible at this moment. All you have to do is to visit the following link below:
http://www.youradoptablessite/admin.php?set=adopts&do=edit&more=XXX
Simply change the 'youradoptablessite' part to your script path, and the highlighted XXX to the adoptables type you are deleting, and it should work out for you just fine. I will add back link to allow admins to delete adoptables in Mys v1.2.1. Sorry about that.