Confluence 7.20.3 class file version error

Hello,

since a few weeks, confluence does not work properly when I run atlas-run. I get the error:

Error creating bean with name 'synchronyProxyFilter'
...
Caused by: java.lang.IllegalStateException: Failed to introspect Class [com.atlassian.synchrony.proxy.web.SynchronyProxyFilter] from ClassLoader [ParallelWebappClassLoader
...
Caused by: java.lang.UnsupportedClassVersionError: org/eclipse/jetty/proxy/ProxyServlet has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0 (unable to load class [org.eclipse.jetty.proxy.ProxyServlet]) (unable to load class [com.atlassian.synchrony.proxy.web.SynchronyProxyServlet])

Because of that, the editor does not load anymore.
This error occurs even when I create the example plugin from atlas-create-confluence-plugin (only things I changed were atlassian.dev.mode, atlassian.disable.caches, jvm memory args)

Versions I use:
AMPS 8.1.2
Atlas SDK 8.2.7
JDK 1.8.0_212
Confluence 7.20.3

Can anyone help?

Regards,
Simon

I am facing the same issue using the SDK on a Windows machine - were you able to resolve this?

Sadly, I still have no fix. I use Windows too, by the way (windows 10)

I can only get it to work with the default version assigned by the SDK when running the atlas-create-confluence-plugin command, i.e. Confluence version 6.14.0