I have been having the same or similar problems all week since i installed it. At first the problem was that San Andreas wasnt downgraded. It has since been downgraded, reinstalled, and it starts working. After 1 crash, usually around Bullworth, it no longer works. A reinstall used to make it work again but now it doesnt work either way. I have added Player.img to the gta.dat file, enabled and disabled dep stuff, changed the resolution to various things, ran it with both Hoodlum exe and without, deleted gtaundergrounds entire documents folder, and pretty much done everything possible to fix it. I can provide PC Specs if needed.
Steam Version, downgraded using steam downgrader.
Mod version 220.127.116.11 and 2.2