Versions

Betweenlands version:

3.4.10

Forge version:

14.23.5.2838

Singleplayer or Multiplayer:

Only tested in singleplayer

Installed mods:

Modlist: https://pastebin.com/EPjf35kU

Description of the problem

How to reproduce:

Add following to the portal dimensions config:
thebetweenlands:octine_block:0/-1

Place octine block in betweenlands, right click with talisman, walk through portal, find yourself at the top of the nether ceiling.

Full config file here: https://pastebin.com/QR3Na1x1

Expected result:

Should spawn somewhere below bedrock ceiling

Hm i'll do some more testing with some of the mods removed, see if it makes a difference.
And yeah it was pretty persistent. I created the portal trees slightly above the ground level (maybe 8-10 blocks higher). It did create a small version of the tree portal on top of the nether ceiling.

Will let you know when i have more info after some testing!

I can't reproduce this with BL only. Usually when there's not enough space to generate a full portal then it generates a small one.
Do you know whether one of your mods decreases the bedrock ceiling or world ceiling in the Nether, e.g. Better Nether?
And does this happen consistently?

When i originally tested it, i created 4 portals and they all spawned on the ceiling.

But after testing a bit more, i did find a few spots where it worked fine in the same world.
At first i thought maybe it depends on if there is no open spot anywhere from the bottom to the top whereever the portal is suppose to spawn (cause some of the ceiling portals didn't really have any room below).
But then i saw one that could have spawned lower down but spawned on the ceiling anyway.

I'll update this ticket if i find anything else, but i can't 100% reproduce this at the moment, it's a bit random it seems.

Hmm, thanks.
I've spawned in at least 20-30 portals and all of them generated properly. It should always generate the portal between Y=8 and Y=actual world height - 16. Actual world height in the nether is usually 128. At which Y coord did your portals generate?

I'll see if i can grab a specific coordinate with a specific seed. Might take a bit though heh.
When i was standing on the nether ceiling, my position was 128 in the F3 screen (the height was the same in my pack and in my test environment with just the betweenlands). The portal was on top of it (the small portal).