The change in question is post-v.3.13, so you wouldn't have noticed it; Geoff made meter growth a constant of 1 per turn until it reaches maximum, but that system has a few
problems. Similarly, the reason it's crashing is that you don't have the latest revision; Geoff added a stealth parameter to hulls and some new effects such as CreateShip and Create Building which are in use. Most likely, since the hulls with the stealth parameters can't be parsed by v.3.13, the ship hulls which are used in premade_ship_designs.txt and starting_fleets.txt don't actually exist, according to the game, therefore the game crashes when it tries to place the starting fleets.
You could verify this by checking the FreeOrion log files. When v.3.14 is released, which probably won't be for a few months at least(?), my content files should work, regardless of whether or not they've been committed.
Anyway, the tree I've made is far from being suitable for FO, but it's at least playable and allows some interesting things, which makes it an improvement over the previous one, IMO. There needs to be a lot more discussion about the progression of empire development and strategy, and IMO,
the nature of the tree itself, before any really significant work can be done.