problem with optifine

[rotwhip3]

hey, so i love FTB, but it runs fairly slow on my computer, so i got optifine on it, optifine works fine, but im scared to go caving because when i try to smother lava with water, it water stays in 1 place, makes the hissing sounds, but dosent spread, im really woried because when i tried to walk over the "obsidian" i fell through and died,


is there any way to fix this, watter is acting weird and its already killed me twice.

thanks for the feedback

 

[rotwhip3]

ehhh disregard tis, i think, upon researching a bit, that i need to use the UNIVERSAL forge...

 

[ThisIsWeirdBro]

Your modpack probably doesn't have Forge 518 or up, which the newest version of Optifine needs to run. Most modpacks have forge 515 at the mo, so you'll need to update your Forge to get it working.