Problem Terasology Pre Alpha is good but...


New Member
Hello, I have a problem with Terasology Pre Alpha (which I think is partially better than newer versions). It works fine and me and my father like to play it and my father has built a giant city over the duration of seven years (since 2013) on the same version because when he tried to load up the world in the version from 2015 it just destroyed the world. He has built many impressive buildings and suddenly the game replaced every block of air with a random block (he had activated the mods "minerals", "morelights", "core", "fences" and "soils" (mod list read from WorldManifest.json)). Reloading the world fixes the air but then every door block is replaced with marble. If you build another door it doesn't get replaced with marble but instead with random minerals. The door function is still there, you can click a door with [E] and it makes the door sounds and the blocks change. My father really wants his world to look nice again and I tried to repair it (no other worlds in the same installation of Terasology are behaving weird) but I failed to do so.

But I have an idea: every block is assigned to a random number in WorldManifest.json or rather some numbers are assigned to blocks and these numbers change seemingly randomly everytimes Terasology saves the world. If I delete the blockIdMap list from the file WorldManifest.json the game replaces every air block with the same random block and reloading the world repairs the issue with the air but the doors are replaced again with marble and newly placed ones are replaced with random minerals. If you could help me understanding how the assigned numbers are generated I could probably fix his world but if you have other ways to fis this issue that would be great. Maybe you could even create a new version of that exact Pre Alpha version of Terasology that leaves gameplay, game behaviour and everything the same as it was in 2013 but fixes the issues of doors being replaced. And only doors do have these isues, no other block (maybe because doors are the only block with a height of two blocks?).

I have put the world, the modified minerals.jar and a copy of my father's installation of Terasology here: I didn't attach the files to this post because they are to big for the server to handle ("The uploaded file is too large for the server to process.").


Org Co-Founder & Project Lead
Hi there - consider me sufficiently impressed that you are indeed talking about the pre-alpha we moved on from years ago, and for what might be the longest lived Terasology world in existence! :)

Do you have screenshots of anything as well? We'd love to see some.

Most game activity has moved to Discord so the forum is somewhat neglected. That'd be a far easier way to help troubleshoot:

For clarity: Are you saying you tried to update the old world in-place, and need to recover it, or do you have backups secured, are able to keep playing the game, but just hope to either get that fix for the old game or a way to bring forward the saved world to more modern versions?

"Block shuffling" so to say is a fairly common bug, and we may be able to help provide more details, although probably it would be better to get from others than me, I'm not so deep in the code these days (having kids will do that ...)

We haven't paid much attention to world stability over the years, but it is an area we need to improve. If you're curious to help research in that area that would be lovely. I would be thrilled to see some sort of save game converter and it should not be that hard to get it to work, even with very old games - fundamentally blocks in the world itself have changed very little, ultimately they're all still just ids in chunk arrays. You've encountered the world manifest which isn't very complex either. Entities would be more difficult but aren't generally involved with basic builds much (indeed other than things like doors and chests)