If any single anime franchise has suffered from production issues, it's almost certainly Kentaro Miura's seminal work, Berserk.
If any single anime franchise has suffered from production issues, it's almost certainly Kentaro Miura's seminal work, Berserk. The dark, demon-ridden series has never been fully adapted by an animation studio, and its 2016 reboot was as poorly received as any in recent memory.