SikuliX NoClassDefFoundError

I'm trying to create a GUI test using SikuliX in Java. I've tried to specify where it should search for my images using ImagePath.setBundlePath(), but i get the following error when i try to run the test:

java.lang.NoClassDefFoundError: org/sikuli/script/ImagePath

And the cause:

Caused by: java.lang.ClassNotFoundException: org.sikuli.script.ImagePath starting from SystemClassLoader[27 modules] with possible defining loaders null and declared parents [org.netbeans.MainImpl$BootClassLoader@65e579dc, ModuleCL@6befa999[org.netbeans.api.annotations.common], ModuleCL@17e6b89c[org.netbeans.api.intent], ModuleCL@1c8e838d[org.netbeans.api.io], ModuleCL@b01b869[org.openide.io], ModuleCL@79f6ed7e[org.openide.awt], ModuleCL@58a8c9b6[org.netbeans.api.progress], ModuleCL@5a61336f[org.netbeans.api.progress.nb], ModuleCL@163531c6[org.netbeans.modules.autoupdate.services], ModuleCL@5affab00[com.se.sem4.group2.Common], ...9 more]
at org.netbeans.ProxyClassLoader.loadClass(ProxyClassLoader.java:224)
at org.netbeans.ModuleManager$SystemClassLoader.loadClass(ModuleManager.java:766)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 38 more
Caused by: java.lang.ClassNotFoundException: org.sikuli.script.ImagePath
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.netbeans.ProxyClassLoader.loadClass(ProxyClassLoader.java:222)
... 40 more

Not sure if this has anything to do with it, but I also get this message:

AL lib: (EE) alc_cleanup: 1 device not closed