Please save in a pokecenter before updating if using a save from a previous version, otherwise you risk corrupting your save. You should again patch a CLEAN YELLOW ROM if patching from the IPS patch. Do NOT apply the patch to an already patched Yellow Legacy ROM. Please be smart, take a backup of your save before updating just to be safe.
PSA: Before you get started patching anything, load your base yellow ROM into rom patcher js (or a hash checker) and check the SHA-1 hash. The base yellow hash should be SHA-1: cc7d03262ebfaf2f06772c1a480c7d9d5f4a38e1. If it is not exactly this, you have a modified or bootleg yellow ROM and you will have to find a real one. Similarly the hash of your 1.0.9 patched ROM should be SHA-1: 5cedd531b157ccebc74dbaae25f7945711975624, again if this is not exactly this, you have done something wrong and should repatch.
Changelog 1.0.9
- Fixed evolution level up moveset bug
- Razor wind item description fixed
- Fixed neeed typo
- Fixed eeveelution in champions room rematch
- Fixed large decrement underflow if on 10
- Changed easy/hard mode messages to start with "Are you sure?"
- Gastly poison gas to 23
- Vermilion trash puzzle resets when you leave the gym
- Erika 4 victreebel gets stun spore
- Fixed super rod encounters showing wrong locations on the pokedex area page
- Fixed buffer overflow bug with pokedex old/good rod encounters
- Fixed exp all party display bug
- Fixed Fuchsia signs displaying pokedex move page
- Fixed a bug where the oak catching pikachu scene breaks boxes
- Switched badge boost text in gyms that were wrong
- Fixed item description for flamethrower tm