SASSOT 1.1.0-1.1.2 seem to have problems with Origins and also pehkui, both the normal and bettercombat versions affected. This mixin error happens with multiple mods with the exact same output but out of my actual modpack I only narrowed down the two mentioned above so far.

Minecraft has crashed!
net.fabricmc.loader.impl.FormattedException: java.lang.RuntimeException: Mixin transformation of net.minecraft.class_1657 failed
at net.fabricmc.loader.impl.FormattedException.ofLocalized(FormattedException.java:63)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:470)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:74)
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)
Caused by: java.lang.RuntimeException: Mixin transformation of net.minecraft.class_1657 failed
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:427)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.tryLoadClass(KnotClassDelegate.java:323)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.loadClass(KnotClassDelegate.java:218)
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:112)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
at net.minecraft.class_2966.method_12851(class_2966.java:54)
at net.minecraft.client.main.Main.main(Main.java:166)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:468)
... 2 more
Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError: An unexpected critical error was encountered
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:392)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:234)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:202)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:422)
... 9 more
Caused by: org.spongepowered.asm.mixin.injection.throwables.InjectionError: Critical injection failure: Constant modifier method modifiedSweepingRange(D)D in sassot.mixins.json:entity.player.PlayerEntityMixin from mod sassot failed injection check, (0/1) succeeded. Scanned 1 target(s). Using refmap sassot-refmap.json
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.postInject(InjectionInfo.java:468)
at org.spongepowered.asm.mixin.transformer.MixinTargetContext.applyInjections(MixinTargetContext.java:1384)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyInjections(MixinApplicatorStandard.java:1062)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyMixin(MixinApplicatorStandard.java:402)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:327)
at org.spongepowered.asm.mixin.transformer.TargetClassContext.apply(TargetClassContext.java:421)
at org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:403)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:363)
... 12 more

Same with pehkui

This also happen with the mod Things, seems that the problem is a mixin conflict with the library reach-entity-attributes. A quick search in github shows that this library is used in a lot of mods.

And probably #45 is related to this.
EDIT: maybe not related, but MythicMetals uses the library

Thank you all for reporting this issue. This issue should now have been solved in the latest v1.1.3-1.20.1(+bettercombat) versions.
As mentioned by SrGnis, the solution for vanilla SASSOT using the Reach Entity Attributes library. Crash issues from the +bettercombat version have also been fixed.
This thread will now be closed, please feel free to report any persisting issues in the future.