JUnit5 PreconditionViolationException: Could not load class with name transit.StopTimesTest

I'm trying to test my code with JUnit5 but it keeps giving me this:

Oct 15, 2017 3:30:24 PM org.junit.platform.launcher.core.ServiceLoaderTestEngineRegistry loadTestEngines INFO: Discovered TestEngines with IDs: [junit-jupiter] Internal Error occurred. org.junit.platform.commons.util.PreconditionViolationException: Could not load class with name: transit.StopTimesTest at org.junit.platform.engine.discovery.ClassSelector.lambda$getJavaClass$0(ClassSelector.java:71) at java.util.Optional.orElseThrow(Optional.java:290) at org.junit.platform.engine.discovery.ClassSelector.getJavaClass(ClassSelector.java:70) at org.junit.jupiter.engine.discovery.DiscoverySelectorResolver.lambda$resolveSelectors$2(DiscoverySelectorResolver.java:60) at java.util.ArrayList.forEach(ArrayList.java:1249) at org.junit.jupiter.engine.discovery.DiscoverySelectorResolver.resolveSelectors(DiscoverySelectorResolver.java:59) at org.junit.jupiter.engine.JupiterTestEngine.resolveDiscoveryRequest(JupiterTestEngine.java:50) at org.junit.jupiter.engine.JupiterTestEngine.discover(JupiterTestEngine.java:43) at org.junit.platform.launcher.core.DefaultLauncher.discoverRoot(DefaultLauncher.java:109) at org.junit.platform.launcher.core.DefaultLauncher.discover(DefaultLauncher.java:79) at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:47) at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:237) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

Process finished with exit code -2 Empty test suite.