# it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap in 253.x **URL:** \ **Category:** IntelliJ Platform\ **Created:** [October 20, 2025, 7:01pm UTC](https://platform.jetbrains.com/t/it-unimi-dsi-fastutil-objects-reference2objectopenhashmap-in-253-x/2966 "2025-10-20T19:01:03Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![kolchinmax](https://sea1.discourse-cdn.com/flex001/user_avatar/platform.jetbrains.com/kolchinmax/32/374_2.png) [@kolchinmax](https://platform.jetbrains.com/u/kolchinmax)\ **Post date:** [October 20, 2025, 7:01pm UTC](https://platform.jetbrains.com/t/it-unimi-dsi-fastutil-objects-reference2objectopenhashmap-in-253-x/2966/1 "2025-10-20T19:01:03Z")
Hi there, Any one else cannot build a plugin with the IDEA 253.x due to the below error? `Caused by: java.lang.ClassNotFoundException: it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap` See [2025.3 EAP doesn't provide `it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap` · Issue #220 · JetBrains/gradle-grammar-kit-plugin · GitHub](https://github.com/JetBrains/gradle-grammar-kit-plugin/issues/220) for more details. Regards, Maksim ---
**Author:** ![yuriy.artamonov](https://sea1.discourse-cdn.com/flex001/user_avatar/platform.jetbrains.com/yuriy.artamonov/32/48_2.png) [@yuriy.artamonov](https://platform.jetbrains.com/u/yuriy.artamonov)\ **Post date:** [October 22, 2025, 12:21pm UTC](https://platform.jetbrains.com/t/it-unimi-dsi-fastutil-objects-reference2objectopenhashmap-in-253-x/2966/3 "2025-10-22T12:21:03Z")
Hi, I cannot reproduce the problem in 253-EAP-SNAPSHOT. How your plugin.xml dependencies look like? ---
**Author:** ![yuriy.artamonov](https://sea1.discourse-cdn.com/flex001/user_avatar/platform.jetbrains.com/yuriy.artamonov/32/48_2.png) [@yuriy.artamonov](https://platform.jetbrains.com/u/yuriy.artamonov)\ **Post date:** [October 22, 2025, 12:40pm UTC](https://platform.jetbrains.com/t/it-unimi-dsi-fastutil-objects-reference2objectopenhashmap-in-253-x/2966/4 "2025-10-22T12:40:43Z")
Also, I see this is not runtime problem but in Gradle tools, right ? It is probably due to the fact that we moved libraries from Core subsystem to dedicated modules > > > \*\*Describe the bug\*\* > > \`\`\` > Execution failed for task ':frontend:file:generatePars…er'. > \> Exception in thread "main" java.lang.NoClassDefFoundError: it/unimi/dsi/fastutil/objects/Reference2ObjectOpenHashMap > at com.intellij.openapi.util.ObjectTree.\(ObjectTree.java:28) > at com.intellij.openapi.util.Disposer.\(Disposer.java:21) > at com.intellij.core.CoreApplicationEnvironment.\(CoreApplicationEnvironment.java:84) > at com.intellij.core.CoreApplicationEnvironment.\(CoreApplicationEnvironment.java:76) > at org.intellij.grammar.LightPsi$MyParsing.\(LightPsi.java:152) > at org.intellij.grammar.LightPsi.\(LightPsi.java:55) > at org.intellij.grammar.Main.main(Main.java:38) > Caused by: java.lang.ClassNotFoundException: it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap > at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) > at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) > at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) > ... 7 more > \`\`\` > > \*\*To Reproduce\*\* > > Compile a Gradle subproject under IntelliJ \`253.25908.13-EAP-SNAPSHOT\`. > > Sample project to repro: > \* check out https://github.com/VirtusLab/git-machete-intellij-plugin/pull/2142 > \* switch to JDK 21+ > \* \`./gradlew :frontend:file:generateParser\` > > \*\*Expected behavior\*\* > > Compilation passes. > > \*\*Environment:\*\* > - OS: macOS > - Gradle Grammar-Kit Plugin Version: latest (2022.3.2.2) > - Gradle Version: 9.0.0 > > \*\*Additional context\*\* > Nothing in particular. ---
**Author:** ![kolchinmax](https://sea1.discourse-cdn.com/flex001/user_avatar/platform.jetbrains.com/kolchinmax/32/374_2.png) [@kolchinmax](https://platform.jetbrains.com/u/kolchinmax)\ **Post date:** [October 25, 2025, 9:10am UTC](https://platform.jetbrains.com/t/it-unimi-dsi-fastutil-objects-reference2objectopenhashmap-in-253-x/2966/5 "2025-10-25T09:10:59Z")
@yuriy.artamonov No, the same issue with the latest snapshot version, below is my configuration: `intellijIdea("253.27864-EAP-CANDIDATE-SNAPSHOT") { this.useInstaller = false }` > It is probably due to the fact that we moved libraries from Core subsystem to dedicated modules Okay, what need to be adapted in the plugin to align with the change? I don’t see any relevant at [Incompatible Changes in IntelliJ Platform and Plugins API | IntelliJ Platform Plugin SDK](https://plugins.jetbrains.com/docs/intellij/api-changes-list.html). Thanks! ---
**Author:** ![kolchinmax](https://sea1.discourse-cdn.com/flex001/user_avatar/platform.jetbrains.com/kolchinmax/32/374_2.png) [@kolchinmax](https://platform.jetbrains.com/u/kolchinmax)\ **Post date:** [October 28, 2025, 8:24pm UTC](https://platform.jetbrains.com/t/it-unimi-dsi-fastutil-objects-reference2objectopenhashmap-in-253-x/2966/6 "2025-10-28T20:24:25Z")
@yuriy.artamonov Sorry, I’ve missed your question, see the answer below. > [@yuriy.artamonov](#): > > I cannot reproduce the problem in 253-EAP-SNAPSHOT. How your plugin.xml dependencies look like? ```xml com.intellij.modules.platform com.intellij.modules.lang ``` Thank you in advance! ---
**Author:** ![kolchinmax](https://sea1.discourse-cdn.com/flex001/user_avatar/platform.jetbrains.com/kolchinmax/32/374_2.png) [@kolchinmax](https://platform.jetbrains.com/u/kolchinmax)\ **Post date:** [November 8, 2025, 6:29pm UTC](https://platform.jetbrains.com/t/it-unimi-dsi-fastutil-objects-reference2objectopenhashmap-in-253-x/2966/7 "2025-11-08T18:29:30Z")
I opened a bug at YouTracker ([https://youtrack.jetbrains.com/issue/IJPL-217565/it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap-in-253.x](https://youtrack.jetbrains.com/issue/IJPL-217565/it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap-in-253.x)), because I’m blocked now and not able to continue the development. The IDEA version which worked before is not available anymore.