not working in multiplayer
Is this on purpose or just not enough information about mod?

That is not on purpose. I will look into it when I get the chance. :)

This is fixed. Closing the thread.

I guess this is where you would like our discussion moved?
I'll test without any mods, first on the current world and then, if that doesn't change anything, on a fresh world with just this mod.

So, the problem isn't fixed by using just this mod.
I've tried removing all mods but this one from my current world: Purple Stuff.
I've made a new world that has only ever seen this mod: Purple Stuff.
I then deleted the mod file and reloaded the world. Still, Purple Stuff.

Wierd.
In that case, here are the posibillities i see at the moment:
It could be that you are running the experimental version of SE, since I haven't tested on that.
Some files in SE could be corrupted, so try verifying the game cache.
Other than that, try deleting the file C:\Users\(USERNAME)\AppData\Roaming\SpaceEngineers\Mods\596198369.sbm and try it again.
That is the mod cache, so it will be redownloaded. It could be a problem with that file.

Experimental doesn't exist anymore, it's either the current branch or a previous one; I'm running the current.
I'll give verifying a shot, but since everything's fine without the mod installed, I doubt it will help.
EDIT: All files successfully validated, so there were no problems with any of the files.
I also deleted the cache already, as I said in my previous comment. I guess I should have specified what exactly I did, though.

Ah. Okay. In that case I am not sure why this is happening, since everything works fine for me, and you are the only one to report this issue so far.
I will try confering with Digi, and get back to you.

I could maybe try uploading an affected world, if you think that would help.

Sure thing.

Alright, here's the world:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1153691667

Digi suggested something that should fix the issue.
I will try to get an update out some time tomorrow.

There we go. I fixed the bug.
It was caused by a semi-removed custom material, originally from the source mod by Digi.
I just removed the material files, and all is now fine.
It should be fine if you download it now.
Also, the bug will not have any permanent impact on your worlds.

I figured it wouldn't, since the issue went away if I uninstalled the mod.
It's great to have it fixed, thank you!

No problem. :)