Which distribution/version of JAVA do you have installed on your machine? Did you install it yourself or was it already installed with the OS? Which version of Ubuntu do you use? If I remember well I had to install (manually) another version of JAVA than the version provided with the OS because it didn't work correctly. I think that the preinstalled version even didn't work in Firefox (not detected) I don't know if the following versions of Ubuntu fixed this. I think (I'm not sure I remember well) that the version of JAVA installed with Ubuntu wasn't the official release by Sun but a tweaked version... Again, I'm not sure. It's been ages

A silly question but ... how do you launch Lemmini? Do you rightclick "lemmini.jar" and choose "Open with

I like efficiency. I'd favour keeping the files as small as possible (by keeping the tileset and level data separate), but if we do this we have to make absolutely sure that we don't end up with a situation where you have levels without the data files needed to run them. Someone mentioned a way of automatically detecting missing tilesets that you need to run a level. I like that idea very much.

IMHO keeping the tilesets and level data separate would be the best option. The game engine could scan for available (installed) tilesets and thus detects missing ones without having to exit brutally This tilesets scan could either be performed during the main game initialization (to retrieve a list of all the styles available) or on the fly when loading a level (checking if the current style(s) exists on disk and adding the style(s) to the list if they aren't already stored in that list). Doing this we could use several styles in a single level and we could also edit existing styles and create new ones  This is what I thought for my project...

Anyway if we'll use embedded styles in level files, we should consider a level converter at a certain point...

I had already installed and played Lemmini on Ubuntu in the past (version 8.04 aka Hardy Heron) and it worked like a charm. I think I just needed to set the sound profile... In short, nothing that complicated 

Re: pic: How did you get there without using any time or skills?

Well I don't know if it has something to do with "Amiga Forever" or my Lemmings ADFs, but the skill panel seems not to refresh. The only working things are the IN/OUT lemmings and the release rate. The other buttons don't change. So YES I used skills (bashers, miners, blockers and builders).

That was DragonsLover's "corrected version". I don't know how that was done exactly, but it might be worth checking.

Yes indeed. If someone knows where to find this correction version, this would interest me too

or have a level filer converter? (maybe a feature of the Lemmix editor?) 

A first thing to know about these levels is that water only exists in the Amiga version, not in the DOS version. In the DOS version it's simply empty where the Amiga version has water. So in the DOS version lemmings die by falling into the void, and they die by drowning into the water in the Amiga version.

I've just checked Tricky 7 in the Amiga version and water on the right of the level is indeed fake (between the 2 last pillars). This confirms the index theory    Look at the attached screenshot.

EDIT: The Windows version has also no water traps in these levels

Maybe a stupid question... How does the original  Holiday Lemmings game interpret/detect/know that the other doors in this level are fake? Something to do with coordinates? Something in the level description which overwrites the trigger effects specified in the graphic sets? You told about gaps in the interactive objects indices in a level, what happens in the original DOS game concerning these indexes? I don't know such a rule which mentions that such or such indice gives a fake door... So this interests me Same thing with other traps?

Or use Foobar2000 with the foo_gep.dll component