build issue

build.gradle

@@ -45,18 +45,20 @@ javadoc {
     options.addStringOption('Xdoclint:-missing', '-quiet')
 }
 
+tasks.named('jar') {
+    archiveClassifier.set('plain')
+}
+
 // Adds the Hytale server as a build dependency, allowing you to reference and
-// compile against their code without bundling it. When a local install is
-// present, we still use its jar for launching the server in IDE run configs.
+// compile against their code without bundling it. The local Hytale server jar
+// is used directly by runServerJar below, but it must not be placed on
+// runtimeClasspath because shadowJar would bundle it into the plugin jar.
 dependencies {
     compileOnly("com.hypixel.hytale:Server:$hytale_build")
     testCompileOnly("com.hypixel.hytale:Server:$hytale_build")
     testRuntimeOnly("com.hypixel.hytale:Server:$hytale_build")
     testImplementation("org.junit.jupiter:junit-jupiter:5.11.4")
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
-    if (hasHytaleHome) {
-        runtimeOnly(files("$hytaleHome/install/$patchline/package/game/latest/Server/HytaleServer.jar"))
-    }
 
     // Your dependencies here
 }
@@ -140,7 +142,7 @@ if (hasHytaleHome) {
         classpath = files(serverJar)
         workingDir = serverRunDir.absolutePath
         doFirst {
-            def modPaths = [shadowJarTask.get().archiveFile.get().asFile.parentFile.absolutePath]
+            def modPaths = [shadowJarTask.get().archiveFile.get().asFile.absolutePath]
             if (load_user_mods.toBoolean()) {
                 modPaths << "${hytaleHome}/UserData/Mods"
             }