kay, mystic Angel. from the error message
File: C:\Users\Dare\AppData\Local\Ironclad Games\Sins of a Solar Empire\Mods-Diplomacy v1.01\Bailknight's Graphic Mod\GameInfo\FrigatePhaseLongRange.entity
Label: allegianceDecreasePerRoundtrip
Line Number:152
Line Contents:maxShadow 1.000000
what I can tell is that I can't put anything but "allegianceDecreasePerRoundtrip" where it is. I get that it's in the wrong slot, but how do I make the game realise I want something ELSE there.
The most important thing for you to know is that you can't switch the structure of the ship entity files around. There are a select few lines that affect structure (such as changing the number of weapons allows you to add or remove entire weapon entries), but, in general, you must keep every line in the exact place you find it in stock material.
So, as far as ship entity files are concerned, you're better off just duplicating an existing file and making changes to the values only. Working from scratch or adding bits in a piecemeal fashion will get almost anyone into trouble. Working with ability and buff entity files, on the other hand, is where you really have to know what line labels lead to what additions or subtractions from the coding (though I still say copy and paste from another file that produces the same or very similar results).
As for that specific error in the quote, I can't say exactly what's causing it because I don't know the circumstances. If it popped up as an isolated issue, then it would seem that you have a duplicate "maxShadow 1.000000" where "allegianceDecreasePerRoundtrip" is supposed to be (maxShadow should be right above allegiance). There could be another cause, but since the allegiance prompt is the final line of the file I don't think so. On the other hand, if there were errors preceding this one, then you've most likely added an additional line somewhere else in the file, and the issue has trickled down to the final line. I'd need to see the entire entity file to know for sure.
What I used to do, and what you can do also, is open up a similar entity file that you know works, and then compare it with this one line by line. It's tedious, of course, but it'll help you track down the problem and you'll get to know the structure of the entity files a bit better. Win/win, I'd say.
On a side note, I'm interested in hearing more about Eclipse and Ant. I recall you posting about Eclipse a couple of months ago. I can look that thread up and figure out what I need to from there, but Ant interests me as well. I wouldn't mind if you could share a few of the major selling points of the program.