Issues executing JAR files via testrunner.bat

Hi all,

I am using SoapUI 5.0.0 open sources version, and I am encountering issues in one of my test cases when I am executing a .jar file in the Groovy script. My script looks like this:

def groovyUtils = new com.eviware.soapui.support.GroovyUtils(context)
def filepath = new File(groovyUtils.projectPath)
def proc = ""java -jar seleniumFirefox.jar".execute(null, filepath)

I encounter issues only when I try running this test case through the %SOAPUI_HOME%/bin/testrunner.bat file on the command line. I've tried running this on two different machines, and I get the same error on both machines:

15:03:29,906 INFO [SoapUITestCaseRunner] running step [SeleniumTest]
15:03:30,722 ERROR [log] runSelenium err:
java.lang.UnsupportedClassVersionError: seleniumFirefox : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)
Exception in thread "main"

There seems to be a mismatch in Java version - but I'm not sure not to solve this issue. Any suggestions? Thanks!