Summary:
Sometimes, for a period of time, Act 7: Climactic Crash cannot be released. The charging animation will occur, the flash that indicates full charge will occur, but then when releasing the skill manually, the skill fails as if the user were interrupted. Once the bug occurs, Act 7 will remain unusable for a long duration. I am not sure what precisely causes the bug to end, but switching locations (e.g. exiting a mission) will restore normal functionality.
Difficulty:
Intermediate. The bug does not happen that frequently, but when it does, it renders the skill Act 7 unusable, which is frustrating, as Act 7 is the primary damaging skill for puppets.
Occurrence:
Seems to happen frequently when the boss of Feth Fiada spawns enemies. Happens in other situations as well, but I do not know exactly what causes the bug.
Details:
See attached clip. You can see me loading act 7 fully as the screen flashes but I cannot execute the skill.