Fastload+1.18.2-1.20-3.3.8

in my case I've updated the Mods: Spark and Fastload at the same time.
Spark caused the issue. I've downgraded Spark and now the newest Fastload Version is working well.

I have no problem launching my 1.18.2 Fabric client. Could it be that you modified the fabric.mod.json file that is inside the .jar file? Maybe try redownloading the mod.

When i have some problems that aren't related to Fastload I can see this issue with Fastload. So when I fix my problem, issue with Fastload will disappear too.

I think I saw issue like mine but rn I can't find it.