Hi. I think there’s a glitch in cathedral between level 1 and 2 in
“Pasaje de Leoric” (not know in english should be “leoric’s passage”?)
Where the first time we reach deckard cain; and he appears running out in history mode near the “blue hole”.
Zombies and monsters are in that place and I cant reach and kill them 🥲
And goblins too so they run and disappear Into that room.
It doesnt allow me add a picture or a link to show 
postimg.cc/gxgbCMgZ
I suppose you were playing in Campaign (story) mode.
After you saved Cain, he opened a secure door/stairs (top right in the screenshot).
You should follow him into this door/stairs which would brought you back to the ground. Then use the waypoint to go back to town.
Later in the story, you’ll come back through the stairs and then go to the right which has a door to continue the story. You are not supposed to go left (blue hole).
Next time, please try the New Player Help forum first.
No, this is in Adventure mode. Campaign is scripted, with the same monsters appearing in the same spots.
OP’s screenshot does show monsters where they shouldn’t be. Have tried this myself but couldn’t replicate, so this may be a rare issue. Then again, it’s not an area I visit often.
Also, this looks like it’s on a console… should probably be moved/reported in Console Bug Report.
The screenshot’s from console, but I’m fairly sure we’ve also seen reports of it on PC too, i.e. I don’t think it’s a platform-specific bug.
All the reports I’ve ever seen of it were on console.
E.g. there’s multiple reports of it in this thread, and it turned out they were all console players: Can't reach goblin in Leoric's Passage - #11 by anon52517139
Anecdotally, I can say I’ve farmed that area hunting Rainbow Goblins. 1000+ runs, and I’ve never seen enemies over there. Doesn’t mean it can’t happen on PC, as not all players will experience all glitches/bugs, but it does seem like it’s either a console exclusive bug, or at least that it’s far more common on console.
I believe it was bug fixed (on PC) quite some time ago, but that never happened for consoles. It is still a regular issue, near 100% instance of mobs and goblins being across the chasm and unreachable. It sucks when it’s a menagerist goblin - yes, I had that happen once. I was not impressed.
The real issue is that we report it, and the bug doesn’t get fixed by Blizzard, let alone acknowledged.
Thanks
Im new in the forum
Didnt know i was posting in pc area 
Its ps4
Its campaign mode, seasonal actually at least happened to me…
I’ve been able to get to what looks like empty space where the nearest zombie is. Playing ps4, can use teleport or blood rush to do it. Possibly some other movement skills would work as well? Might be easier on PC due to mouse.