Historian Achievement - Environment logs 23/25 issue and a potential solution

I've noticed there are a lot of posts from people stuck on 23/25 data logs for the Environment section of the Codex. This, in turn, prevents them from getting the Historian achievement and was a nuisance for me for a while as well. Hopefully the following will be of help.

I've seen people say this issue is related to the fact that a lot of the later levels (Titan's, Necropolis, Argent D'Nur) keep appearing as unread in their codex, regardless of completion and the solution could be to replay them until the problem fixes itself. That was my experience with those entries as well and it threw me off for a long while until I realized it's not related in the slightest.

The real problem for me was that I had an entire section missing from the Environment section. Because the entire section was not there, there were no hints to help me either. The data logs did not appear on the level map as uncollected white markers either, at least for me, so that's a problem as well.

The level I'm talking about is Lazarus Labs and the way to solve this problem is by getting the two data logs that add environment entries. The first one is just a bit after the beginning of the level - make your way through the corridors until you reach two holograms of Olivia Pierce and another UAC member discussing the Slayer. Right next to them in a small space under an office window is the first data log.

At this point if you go into the environment section of the Codex, Lazarus Labs should have an entry and log 002 should appear as unlocked (that's the log you just got). Your log count for the Environment section should be at 24/25 now. If you check the first log entry you can see the hint that the other log is at the automap location. Make your way further into the level and at some point you will pass a grate mounted onto a wall, close to the ground. It's a little different from the regular grates you might see around and if you get close you will get a prompt to activate it. Do so, enter the now open vent, drop down and make your way through the tunnels (there are no enemies inside) until you reach the automap location.

Once you activate the automap you should automatically receive the other Lazarus Labs Environment data log and your Historian achievement should pop immediately.

I hope this helped you finally get that achievement. I had given up on getting it for the longest time because I thought it was just bugged, but it turns out the solution was annoyingly obvious.

Cheers!