Are you playing more than one character?

Have you completed the Precursor on *one* character - four years ago - but this is a *second* character who has not made it?

Also, the door to Zanon's laboratory is never locked, go back there? Are you trying to go to the wrong door? You should be going to the place where you actually handed in the clockwork pieces, and talking to Associate Zanon. This door is NEVER locked. The game is not capable of locking it.

Remember that if you go to Associate Zanon's Workshop on the ground floor level, you need to take the *lift* - not another door. It goes up to the upper level of his workshop, which is also accessible by an always-unlocked door from the upper platforms of the city.

If you're seeing a locked door, you're standing at the wrong door, because neither of the doors to the laboratory are even capable of locking.