I can't add spigot plugins

I have unlocked the spigot server plugin already. So, while I try, I cannot. Here's why:

Executing Gradle task: buildLatestSpigot
Build info: MCreator 2021.3.52418, spigot-1.16.5, 64-bit, 3969 MB, Windows 10, JVM 16.0.2, JAVA_HOME: C:\Program Files\Pylo\MCreator\jdk
 
java.lang.NoClassDefFoundError: Could not initialize class...
...FAILURE: Build failed with an exception.
* What went wrong:
Could not initialize class org.codehaus.groovy.reflection.ReflectionCache
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 9s
 
BUILD FAILED
Task completed in 10 seconds