java.lang.ClassNotFoundException: org.springsource.loaded.ri.ReflectiveInterceptor

I was stuck today on some unhelpful error message when trying to run my Grails app on Intellij IDEA 15.0.6:

Exception in thread "main" java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1426)
    at com.intellij.rt.execution.CommandLineWrapper.main(CommandLineWrapper.java:46)
Caused by: java.lang.NoClassDefFoundError: org/springsource/loaded/ri/ReflectiveInterceptor
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:125)
    ... 6 more
Caused by: java.lang.ClassNotFoundException: org.springsource.loaded.ri.ReflectiveInterceptor
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    ... 7 more

This Stack overflow answer solved my issue: I had to go into the .idea folder located in the root of my project, open the workspace.xml file and set the dynamic.classpath option to false.