Issue when fighting final Sekhmet trail boss in Demon Form

https://imgur.com/a/hAnF0P8

It says "Metadata/Effects/Spells/maneuver_mechanics/Afterimage/DemonAfterimage.ot is non-virtual and does not have a physical file
This happens every time I fight him in Demon Form, at some point this error will occur and the game will crash. Then when I go back in, the honour i've lost remains but his health is back to the beginnig (the fight resets)