here is the error

"java.lang.NoClassDefFoundError: kotlinx/datetime/Clock$System
at knot//opekope2.optigui.internal.selector.DateSelector.getToday(IndependentSelectors.kt:14)
at knot//opekope2.optigui.internal.selector.DateSelector.createFilter$lambda$2$lambda$0(IndependentSelectors.kt:39)
at knot//opekope2.optigui.filter.PreProcessorFilter.evaluate(PreProcessorFilter.kt:21)
at knot//opekope2.optigui.filter.DisjunctionFilter.evaluate(DisjunctionFilter.kt:21)
at knot//opekope2.optigui.filter.DisjunctionFilter.evaluate(DisjunctionFilter.kt:10)
at knot//opekope2.optigui.filter.ConjunctionFilter.evaluate(ConjunctionFilter.kt:21)
at knot//opekope2.optigui.filter.ConjunctionFilter.evaluate(ConjunctionFilter.kt:10)
at knot//opekope2.optigui.filter.PostProcessorFilter.evaluate(PostProcessorFilter.kt:33)
at knot//opekope2.optigui.filter.FirstMatchFilter.evaluate(FirstMatchFilter.kt:22)
at knot//opekope2.optigui.internal.filter.ContainerMapFilter.evaluate(ContainerMapFilter.kt:10)
at knot//opekope2.optigui.internal.TextureReplacer.replaceTexture(TextureReplacer.kt:117)
at knot//net.minecraft.class_332.localvar$ede000$optigui$drawTextureMixin(class_332.java:788)
at knot//net.minecraft.class_332.method_25293(class_332.java)
at knot//net.minecraft.class_332.method_25302(class_332.java:420)
at knot//net.minecraft.class_332.method_25290(class_332.java:416)
at knot//net.minecraft.class_476.method_2389(class_476.java:36)
at knot//net.minecraft.class_465.method_25420(class_465.java:189)
at knot//net.minecraft.class_437.method_47413(class_437.java:111)
at knot//net.minecraft.class_757.mixinextras$bridge$method_47413$144(class_757.java)
at knot//net.minecraft.class_757.wrapOperation$chj000$fabric-screen-api-v1$onRenderScreen(class_757.java:3923)
at knot//net.minecraft.class_757.mixinextras$bridge$wrapOperation$chj000$fabric-screen-api-v1$onRenderScreen$145(class_757.java)
at knot//net.minecraft.class_757.wrapOperation$fbe001$spruceui$onRenderScreen(class_757.java:9438)
at knot//net.minecraft.class_757.method_3192(class_757.java:549)
at knot//net.minecraft.class_310.method_1523(class_310.java:1361)
at knot//net.minecraft.class_310.method_1514(class_310.java:947)
at knot//net.minecraft.client.main.Main.main(Main.java:265)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:506)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:72)
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at com.modrinth.theseus.MinecraftLaunch.relaunch(MinecraftLaunch.java:87)
at com.modrinth.theseus.MinecraftLaunch.main(MinecraftLaunch.java:18)
Caused by: java.lang.ClassNotFoundException: kotlinx.datetime.Clock$System
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source)
at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.loadClass(KnotClassDelegate.java:239)
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:119)
at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
... 33 more
A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Thread: Render thread
org_jetbrains_kotlinx_kotlinx-coroutines-core-jvm: kotlinx-coroutines-core-jvm 1.10.2
org_jetbrains_kotlinx_kotlinx-coroutines-jdk8: kotlinx-coroutines-jdk8 1.10.2
org_jetbrains_kotlinx_kotlinx-datetime-jvm: kotlinx-datetime-jvm 0.7.1
org_jetbrains_kotlinx_kotlinx-io-bytestring-jvm: kotlinx-io-bytestring-jvm 0.8.0
org_jetbrains_kotlinx_kotlinx-io-core-jvm: kotlinx-io-core-jvm 0.8.0
org_jetbrains_kotlinx_kotlinx-serialization-cbor-jvm: kotlinx-serialization-cbor-jvm 1.9.0
org_jetbrains_kotlinx_kotlinx-serialization-core-jvm: kotlinx-serialization-core-jvm 1.9.0
org_jetbrains_kotlinx_kotlinx-serialization-json-jvm: kotlinx-serialization-json-jvm 1.9.0
fabricloader: Fabric Loader 0.17.2
mixinextras: MixinExtras 0.5.0
ferritecore: FerriteCore 8.0.0
firstperson: FirstPerson 2.5.0"

Duplicate of: #169
Also see: #72