For us Steam players, our version of GTA San Andreas differs from the one on SAMP. Having a different version, us Steam users usually find ourselves constantly crashing on servers. Well for everyone else like me who has GTA on Steam, here's how you install SAMP and downgrade GTA.
Firstly, check this video out on how to download SAMP from Steam.
Now you have to downgrade it. Download this program https://gzwn.net/gta/sa/GTASA_12-9-14_Steam_to_V1_DG.exe , run it in your SAMP folder, wait for it to downgrade everything, and you're done.
Sources:
WillisNation's Video
https://steamcommunity.com/sharedfiles/filedetails/?id=382583124