Minecraft version:1.17.0
Fabric Loader version: 0.12.2
Fabric API version: 0.36.0-1.17
Optifabric version: 1.11.20
Optifine version: Preveiw_optifine_hd_ug9_pre26

Crash log: https://pastebin.com/trLWKwaP

Similar to these post:

#386
#394
#398

Read your log, it tells you whats wrong. It says you need .8-.12 and you have .12.2, you are on 1.17 and not 1.17.1 which is the version you had downloaded for fabric. Please let me know if this helps!

I see now, thank you. My mistake on that, thinking that just updating & using the latest version would work, even if was just .2 versions ahead of what what mod can read as the version range it can use.