Shading & relocation

paper-dispatch is a library, not a plugin — it is not on the server, so it must be bundled into your jar. And it must be relocated while you do so.

Relocation is not optional here

Every plugin on a server shares one classloader hierarchy. Two plugins that shade the same unrelocated fr.robie.paperdispatch package can pick up each other's classes.

This library has a concrete reason beyond version skew: OfflinePlayerCache's global instance is static, so without relocation which plugin owns it becomes classloader-dependent — and the symptom appears in the other plugin, looking like someone else's bug.

Relocate into a package you own, e.g. com.yourplugin.libs.paperdispatch.

Maven

pom.xml

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>3.6.2</version>
    <executions>
        <execution>
            <phase>package</phase>
            <goals><goal>shade</goal></goals>
            <configuration>
                <relocations>
                    <relocation>
                        <pattern>fr.robie.paperdispatch</pattern>
                        <shadedPattern>com.yourplugin.libs.paperdispatch</shadedPattern>
                    </relocation>
                </relocations>
            </configuration>
        </execution>
    </executions>
</plugin>

Gradle (Kotlin)

build.gradle.kts

plugins {
    id("com.gradleup.shadow") version "8.3.5"
}

tasks.shadowJar {
    relocate("fr.robie.paperdispatch", "com.yourplugin.libs.paperdispatch")
}

tasks.build {
    dependsOn(tasks.shadowJar)
}

Gradle (Groovy)

build.gradle

plugins {
    id 'com.gradleup.shadow' version '8.3.5'
}

shadowJar {
    relocate 'fr.robie.paperdispatch', 'com.yourplugin.libs.paperdispatch'
}

build.dependsOn shadowJar

Check it worked

Unzip the built jar and look at the package layout:

unzip -l target/yourplugin.jar | grep paperdispatch

Every entry should sit under your relocated package. If you still see fr/robie/paperdispatch/, relocation did not apply — usually because you are shipping the plain jar output instead of the shaded one.

Do not shade the Paper API

Never shade paper-api. It is provided / compileOnly for a reason: the server supplies it. Shading it produces a jar tens of megabytes large that breaks in confusing ways.

minimize()

Shadow's minimize() strips unused classes and cuts jar size, but it can also strip classes only reached by reflection. If something works in your IDE and throws ClassNotFoundException from the built jar, try without it first.