Fix: Java 17 bytecode target on paper module (fixes #3661) - #3662
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Commit 98856a8 only set compileJava release=17 on the root project. The paper subproject still built PaperPlatformProvider (and everything else under paper/src) with the JDK 25 toolchain and no release cap, producing class file version 69, which crashes servers on Java 17-21 with UnsupportedClassVersionError and disables the plugin on load. Setting options.release=17 alone breaks :paper:compileClasspath resolution, since paper-api's dev-bundle metadata is published as JVM-25-only; Gradle infers a TargetJvmVersion=17 requirement from the release flag and refuses to resolve it. Pinning compileClasspath/ runtimeClasspath/testCompileClasspath/testRuntimeClasspath to TargetJvmVersion=25 keeps dependency resolution on the JDK 25 toolchain while compileJava still emits Java 17-compatible bytecode.
dmulloy2
approved these changes
Aug 19, 2026
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Commit 98856a8 only set compileJava release=17 on the root project. The paper subproject still built PaperPlatformProvider (and everything else under paper/src) with the JDK 25 toolchain and no release cap, producing class file version 69, which crashes servers on Java 17-21 with UnsupportedClassVersionError and disables the plugin on load.
Setting options.release=17 alone breaks :paper:compileClasspath resolution, since paper-api's dev-bundle metadata is published as JVM-25-only; Gradle infers a TargetJvmVersion=17 requirement from the release flag and refuses to resolve it. Pinning compileClasspath/ runtimeClasspath/testCompileClasspath/testRuntimeClasspath to TargetJvmVersion=25 keeps dependency resolution on the JDK 25 toolchain while compileJava still emits Java 17-compatible bytecode.