How do I fix this? I'm not too good with mods.

[LKnotOK]

I have no clue how to solve this and would like help.
I've tried deleting optifine and optifabric, and when I enter again to re-install optifine, optifabric comes back.
Then, when i try to start my client, this happens. How do i fix it?

[wagyourtail]

https://discuss.aristois.net/topic/13/how-to-uninstall-optifine-optifine-error-on-startup/1

[Dyiing]

I believe that only deleting the .minecraft/mods/optifine.jar is necessary to fix this issue. If you delete that and it still doesn't work, then the url above mentions how to completely uninstall OptiFine.

It happens because the optifine.jar is shared in the .minecraft/mods/ folder between versions, so if you run optifine on multiple versions it will keep overwriting it, or causing an error since it's not the right version.