[BUG] Progression blocker in "The Heart of Corruption"

Summary: Progression can be blocked in the quest "The Heart of Corruption"

Details: In the quest phase where you have to fight General Rathera in the Converged City in the Crossroads, you're supposed to use a wisp to open the door they're behind or they'll keep summoning undead. However, fast traveling outside of this area before you loot the essence respawns Rathera behind the door, locks the door again, and the wisp disappears, meaning the door no longer can be opened.

The workaround is is to reload a previous save.

This happened with the Steam version.