Yes I also had the same problem with the 2 preview versions of optifine 1.18

Me too, i can confirm that standalone optifine works fine.
And that any preview up to pre7 works fine too.

For me preview_OptiFine_1.18_HD_U_H3_pre7.jar works just fine with optifabric-1.12.7, but OptiFine_1.18_HD_U_H3.jar causes the gam to crash when opening a world or joining a server.

Can confirm will work with preview ok however when opening world and generating view will crash out.

Can confirm this happens with me since pre 6 (here is the crash log from my recent crash)
crash-2021-12-07_20.03.36-client.txt
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both preview and normal crash for optifabric, was working a couple of days ago mustve been a change on optifines end.

both preview and normal crash for optifabric, was working a couple of days ago mustve been a change on optifines end.

Try pre7, its working fine for me

Personally, the game works fine with Optifabric and non-API mods, but it results in a crash when you use OptiFine with Fabric API and Fabric API mods

Can confirm.

1. Loading OptiFabric with OptiFine H3 works fine if both .jar files are the only ones in the mods folder
2. Loading OptiFabric, OptiFine H3, and Fabric API 0.44 crashes the game on loading a saved world.

Using preview_OptiFine_1.18_HD_U_H3_pre7 also does fix this for me.

Can confirm using pre7 version of Optifine has fixed this. That's with other mods and single/multiplayer. 👍

i am using pre7 is didn't work for me