Is anyone else seeing non-stop errors trying to use 2025.1?

Off-Topic
1

After updating to 2025.1 GA, I’m seeing pretty much non-stop errors from Kotlin of the form:

org.jetbrains.kotlin.utils.exceptions.KotlinIllegalArgumentExceptionWithAttachments: Unable to resolve reference class org.jetbrains.kotlin.psi.KtNameReferenceExpression
	at org.jetbrains.kotlin.analysis.api.fir.references.KaFirReferenceResolver.resolve(KaFirReferenceResolver.kt:80)
	at org.jetbrains.kotlin.analysis.api.fir.references.KaFirReferenceResolver.resolve(KaFirReferenceResolver.kt:24)
	at com.intellij.psi.impl.source.resolve.ResolveCache.lambda$resolveWithCaching$1(ResolveCache.java:167)
	at com.intellij.openapi.util.Computable.get(Computable.java:16)
	at com.intellij.psi.impl.source.resolve.ResolveCache.lambda$loggingResolver$4(ResolveCache.java:242)
	at com.intellij.openapi.util.Computable.get(Computable.java:16)
	at com.intellij.psi.impl.source.resolve.ResolveCache.resolve(ResolveCache.java:221)
	at com.intellij.psi.impl.source.resolve.ResolveCache.resolveWithCaching(ResolveCache.java:166)
	at com.intellij.psi.impl.source.resolve.ResolveCache.resolveWithCaching(ResolveCache.java:148)
	at org.jetbrains.kotlin.idea.references.AbstractKtReference.multiResolve(KtReference.kt:33)
	at com.intellij.psi.PsiPolyVariantReferenceBase.resolve(PsiPolyVariantReferenceBase.java:32)
	at org.jetbrains.kotlin.idea.k2.injection.K2KotlinLanguageInjectionContributor.resolveReference(K2KotlinLanguageInjectionContributor.kt:38)
	at org.jetbrains.kotlin.idea.base.injection.KotlinLanguageInjectionContributorBase.injectWithCall(KotlinLanguageInjectionContributorBase.kt:315)
	at org.jetbrains.kotlin.idea.base.injection.KotlinLanguageInjectionContributorBase.findInjectionInfo(KotlinLanguageInjectionContributorBase.kt:184)
	at org.jetbrains.kotlin.idea.base.injection.KotlinLanguageInjectionContributorBase.findInjectionInfo$default(KotlinLanguageInjectionContributorBase.kt:180)
	at org.jetbrains.kotlin.idea.base.injection.KotlinLanguageInjectionContributorBase.computeBaseInjection(KotlinLanguageInjectionContributorBase.kt:160)
	at org.jetbrains.kotlin.idea.base.injection.KotlinLanguageInjectionContributorBase.getBaseInjection$computeAndCache(KotlinLanguageInjectionContributorBase.kt:103)
	at org.jetbrains.kotlin.idea.base.injection.KotlinLanguageInjectionContributorBase.getBaseInjection(KotlinLanguageInjectionContributorBase.kt:115)
	at org.jetbrains.kotlin.idea.base.injection.KotlinLanguageInjectionContributorBase.getInjection(KotlinLanguageInjectionContributorBase.kt:128)
	at com.intellij.psi.impl.source.tree.injected.LanguageInjectionPerformerAdapter.getLanguagesToInject(LanguageInjectionPerformerAdapter.java:22)
	at com.intellij.psi.impl.source.tree.injected.InjectedLanguageManagerImpl.processInPlaceInjectorsFor(InjectedLanguageManagerImpl.java:495)
	at com.intellij.psi.impl.source.tree.injected.InjectedLanguageUtilBase.probeElementsUpInner(InjectedLanguageUtilBase.java:238)
	at com.intellij.psi.impl.source.tree.injected.InjectedLanguageUtilBase.lambda$probeElementsUp$0(InjectedLanguageUtilBase.java:218)
	at com.intellij.openapi.application.impl.ReadActionCacheImpl$allowInWriteAction$1.invoke(ReadActionCacheImpl.kt:41)
	at com.intellij.openapi.application.impl.ReadActionCacheImpl$allowInWriteAction$1.invoke(ReadActionCacheImpl.kt:41)
	at com.intellij.openapi.application.impl.ReadActionCacheImpl.allowInWriteAction(ReadActionCacheImpl.kt:29)
	at com.intellij.openapi.application.impl.ReadActionCacheImpl.allowInWriteAction(ReadActionCacheImpl.kt:41)
	at com.intellij.psi.impl.source.tree.injected.InjectedLanguageUtilBase.probeElementsUp(InjectedLanguageUtilBase.java:217)
	at com.intellij.psi.impl.source.tree.injected.InjectedLanguageUtilBase.enumerate(InjectedLanguageUtilBase.java:160)
	at com.intellij.psi.impl.source.tree.injected.InjectedLanguageManagerImpl.enumerateEx(InjectedLanguageManagerImpl.java:381)
	at com.intellij.codeInsight.daemon.impl.LineMarkersPass.queryLineMarkersForInjected(LineMarkersPass.java:258)
	at com.intellij.codeInsight.daemon.impl.LineMarkersPass.queryProviders(LineMarkersPass.java:217)
	at com.intellij.codeInsight.daemon.impl.LineMarkersPass.lambda$doCollectMarkers$2(LineMarkersPass.java:110)
	at com.intellij.codeInsight.daemon.impl.Divider.divideInsideAndOutsideInOneRoot(Divider.java:96)
	at com.intellij.codeInsight.daemon.impl.LineMarkersPass.doCollectMarkers(LineMarkersPass.java:106)
	at com.intellij.codeInsight.daemon.impl.LineMarkersPass.doCollectInformation(LineMarkersPass.java:79)
	at com.intellij.codeHighlighting.TextEditorHighlightingPass.collectInformation(TextEditorHighlightingPass.java:70)
	at com.intellij.codeInsight.daemon.impl.PassExecutorService$ScheduledPass.lambda$doRun$2(PassExecutorService.java:435)
	at com.intellij.platform.diagnostic.telemetry.helpers.TraceKt.use(trace.kt:28)
	at com.intellij.codeInsight.daemon.impl.PassExecutorService$ScheduledPass.lambda$doRun$3(PassExecutorService.java:431)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.tryRunReadAction$lambda$11(AnyThreadWriteThreadingSupport.kt:522)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.runWithTemporaryThreadLocal(AnyThreadWriteThreadingSupport.kt:204)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.tryRunReadAction(AnyThreadWriteThreadingSupport.kt:522)
	at com.intellij.openapi.application.impl.ApplicationImpl.tryRunReadAction(ApplicationImpl.java:1064)
	at com.intellij.codeInsight.daemon.impl.PassExecutorService$ScheduledPass.lambda$doRun$4(PassExecutorService.java:421)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$executeProcessUnderProgress$14(CoreProgressManager.java:680)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:755)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computeUnderProgress(CoreProgressManager.java:711)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:679)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:77)
	at com.intellij.codeInsight.daemon.impl.PassExecutorService$ScheduledPass.doRun(PassExecutorService.java:420)
	at com.intellij.codeInsight.daemon.impl.PassExecutorService$ScheduledPass.lambda$run$0(PassExecutorService.java:395)
	at com.intellij.openapi.fileTypes.impl.FileTypeManagerImpl.cacheFileTypesInside(FileTypeManagerImpl.java:834)
	at com.intellij.codeInsight.daemon.impl.PassExecutorService$ScheduledPass.lambda$run$1(PassExecutorService.java:395)
	at com.intellij.openapi.application.impl.ApplicationImpl.executeByImpatientReader(ApplicationImpl.java:197)
	at com.intellij.codeInsight.daemon.impl.PassExecutorService$ScheduledPass.run(PassExecutorService.java:393)
	at com.intellij.concurrency.JobLauncherImpl$VoidForkJoinTask$1.exec(JobLauncherImpl.java:267)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:507)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1491)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:2073)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:2035)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:187)
Caused by: java.lang.ClassCastException: class org.jetbrains.kotlin.analysis.low.level.api.fir.sessions.LLFirLibrarySession cannot be cast to class org.jetbrains.kotlin.analysis.low.level.api.fir.sessions.LLFirResolvableModuleSession (org.jetbrains.kotlin.analysis.low.level.api.fir.sessions.LLFirLibrarySession and org.jetbrains.kotlin.analysis.low.level.api.fir.sessions.LLFirResolvableModuleSession are in unnamed module of loader com.intellij.ide.plugins.cl.PluginClassLoader @64e32dd7)
	at org.jetbrains.kotlin.analysis.low.level.api.fir.state.LLSessionProvider.getResolvableSession(LLSessionProvider.kt:40)
	at org.jetbrains.kotlin.analysis.low.level.api.fir.state.LLFirResolvableResolveSession.getModuleComponentsForElement(LLFirResolvableResolveSession.kt:58)
	at org.jetbrains.kotlin.analysis.low.level.api.fir.state.LLFirResolvableResolveSession.getOrBuildFirFor$low_level_api_fir(LLFirResolvableResolveSession.kt:47)
	at org.jetbrains.kotlin.analysis.low.level.api.fir.api.LowLevelFirApiFacadeKt.getOrBuildFir(LowLevelFirApiFacade.kt:108)
	at org.jetbrains.kotlin.analysis.api.fir.references.FirReferenceResolveHelper.resolveSimpleNameReference$analysis_api_fir(FirReferenceResolveHelper.kt:235)
	at org.jetbrains.kotlin.analysis.api.fir.references.KaFirSimpleNameReference.computeSymbols(KaFirSimpleNameReference.kt:48)
	at org.jetbrains.kotlin.analysis.api.fir.references.KaFirReference.resolveToSymbols(KaFirReference.kt:29)
	at org.jetbrains.kotlin.analysis.api.fir.references.KaFirSimpleNameReference.getResolvedToPsi(KaFirSimpleNameReference.kt:60)
	at org.jetbrains.kotlin.analysis.api.fir.references.KaFirReferenceResolver.resolve(KaFirReferenceResolver.kt:36)
	... 61 more

This is a fresh 2025.1 install, not one upgraded from 2024.3 or 2025.1 EAP/Beta/RC.

Is anyone else seeing similar? I’m pretty close to reverting to 2024.3 as my daily driver.

UPDATE: I disabled K2 mode under Settings | Languages & Frameworks | Kotlin and things seem to be improved. Fingers crossed that it stays that way.

2

I have not seen these errors.

3

The exception indeed comes from the K2 mode, so you won’t get an error after disabling it. I’ve created an issue for this problem. We would appreciate it if you could share additional information about your setup.

4

@yanex, it wasn’t anything specific. I installed 2025.1 GA, opened my plugin project, and then immediately started to see those types of errors reported in the bottom-right corner. They seemed to occur when I tried to do anything with references to/usages of Kotlin-based classes from the plugin SDK itself, or when I opened those Kotlin plugin SDK source files.

Note that this is an Ant-based plugin project, not Gradle-based, and I explicitly add the sources to the plugin project SDK based on the intellij-community repo on the branch corresponding to the plugin SDK’s version number, currently 251.23774.

Now that I’ve disabled K2 – which I understand is now enabled by default – I don’t see any such errors and the dev experience is nice and clean.

Let me know if I can provide any other information.

5

Seeing scalc errors after upgrading to 2025.1. The error goes away if I downgrade to 2024.3.5.

scalac: Error: sun.nio.fs.UnixPath
java.io.NotSerializableException: sun.nio.fs.UnixPath
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1187)
at java.base/java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1572)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1529)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1438)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1181)
at java.base/java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:350)
at scala.collection.generic.DefaultSerializationProxy.$anonfun$writeObject$1(DefaultSerializationProxy.scala:38)
at scala.collection.generic.DefaultSerializationProxy.$anonfun$writeObject$1$adapted(DefaultSerializationProxy.scala:37)
at scala.collection.mutable.HashMap$Node.foreach(HashMap.scala:642)
at scala.collection.mutable.HashMap.foreach(HashMap.scala:504)
at scala.collection.generic.DefaultSerializationProxy.writeObject(DefaultSerializationProxy.scala:37)
at jdk.internal.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at java.base/java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1070)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1516)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1438)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1181)
at java.base/java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1572)
at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1529)
at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1438)
at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1181)
at java.base/java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:350)
at org.jetbrains.jps.incremental.scala.local.PackageObjectsData.$anonfun$save$1(PackageObjectsData.scala:35)
at org.jetbrains.jps.incremental.scala.local.PackageObjectsData.$anonfun$save$1$adapted(PackageObjectsData.scala:34)
at scala.util.Using$.resource(Using.scala:296)
at org.jetbrains.jps.incremental.scala.local.PackageObjectsData.save(PackageObjectsData.scala:34)
at org.jetbrains.jps.incremental.scala.local.IdeClientIdea.persistPackageObjectData(IdeClientIdea.scala:133)
at org.jetbrains.jps.incremental.scala.local.IdeClientIdea.compilationEnd(IdeClientIdea.scala:44)
at org.jetbrains.jps.incremental.scala.remote.ClientEventProcessor.process(ClientEventProcessor.scala:45)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.handle(RemoteResourceOwner.scala:61)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.handle$(RemoteResourceOwner.scala:50)
at org.jetbrains.jps.incremental.scala.remote.RemoteServer.handle(RemoteServer.scala:13)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.$anonfun$send$4(RemoteResourceOwner.scala:43)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.$anonfun$send$4$adapted(RemoteResourceOwner.scala:41)
at scala.util.Using$.resource(Using.scala:296)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.$anonfun$send$2(RemoteResourceOwner.scala:41)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.$anonfun$send$2$adapted(RemoteResourceOwner.scala:35)
at scala.util.Using$.resource(Using.scala:296)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.$anonfun$send$1(RemoteResourceOwner.scala:35)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.$anonfun$send$1$adapted(RemoteResourceOwner.scala:34)
at scala.util.Using$.resource(Using.scala:296)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.send(RemoteResourceOwner.scala:34)
at org.jetbrains.jps.incremental.scala.remote.RemoteResourceOwner.send$(RemoteResourceOwner.scala:27)
at org.jetbrains.jps.incremental.scala.remote.RemoteServer.send(RemoteServer.scala:13)
at org.jetbrains.jps.incremental.scala.remote.RemoteServer.sendCommand(RemoteServer.scala:40)
at org.jetbrains.jps.incremental.scala.remote.RemoteServer.compile(RemoteServer.scala:25)
at org.jetbrains.jps.incremental.scala.ScalaBuilder$.$anonfun$compile$4(ScalaBuilder.scala:63)
at scala.util.Either.map(Either.scala:390)
at org.jetbrains.jps.incremental.scala.ScalaBuilder$.$anonfun$compile$3(ScalaBuilder.scala:46)
at scala.util.Either.flatMap(Either.scala:360)
at org.jetbrains.jps.incremental.scala.ScalaBuilder$.$anonfun$compile$2(ScalaBuilder.scala:45)
at scala.util.Either.flatMap(Either.scala:360)
at org.jetbrains.jps.incremental.scala.ScalaBuilder$.compile(ScalaBuilder.scala:43)
at org.jetbrains.jps.incremental.scala.IdeaIncrementalBuilder.build(IdeaIncrementalBuilder.scala:80)
at org.jetbrains.jps.incremental.IncProjectBuilder.runModuleLevelBuilders(IncProjectBuilder.java:1512)
at org.jetbrains.jps.incremental.IncProjectBuilder.runBuildersForChunk(IncProjectBuilder.java:614)
at org.jetbrains.jps.incremental.IncProjectBuilder.buildTargetsChunk(IncProjectBuilder.java:1694)
at org.jetbrains.jps.incremental.IncProjectBuilder.buildChunkIfAffected(IncProjectBuilder.java:1317)
at org.jetbrains.jps.incremental.IncProjectBuilder$BuildParallelizer$1.run(IncProjectBuilder.java:1279)
at com.intellij.util.concurrency.BoundedTaskExecutor.doRun(BoundedTaskExecutor.java:249)
at com.intellij.util.concurrency.BoundedTaskExecutor.access$200(BoundedTaskExecutor.java:30)
at com.intellij.util.concurrency.BoundedTaskExecutor$1.executeFirstTaskAndHelpQueue(BoundedTaskExecutor.java:227)
at com.intellij.util.ConcurrencyUtil.runUnderThreadName(ConcurrencyUtil.java:249)
at com.intellij.util.concurrency.BoundedTaskExecutor$1.run(BoundedTaskExecutor.java:212)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:833)

6

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