RSPS on Linux

Hello, any client I try to run on Ubuntu X86_64 throws the same error:

Exception in thread "Thread-0" java.lang.UnsupportedClassVersionError: com/client : Unsupported major.minor version 52.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:800) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) 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) at com.danny.launcher.LauncherFrame.a(Unknown Source) at com.danny.launcher.LauncherFrame.ru

I’ve done some research and found that the client may have been compiled on a java version that is not compatible with the one that was installed. Downgrading to openjdk-6-jre openjdk-6-jdk from openjdk-7-jre openjdk-7-jdk has not helped and the issue is present across multiple servers.

Any ideas?

compile and run again.
simple as that.