Java multi-room chat example is broken at least

I downloaded this repo and just run as is, it does not work
Nothing happens after "join room"
Maybe other examples also don't work.
Seems like this repo is abandoned, Play 2.7.3 is here 😞
Please update and fix, if there are any Play devs here

EDIT: Crash

|-ERROR in ch.qos.logback.core.joran.spi.Interpreter@26:52 - ActionException in Action for tag [appender] ch.qos.logback.core.joran.spi.ActionException: ch.qos.logback.core.util.DynamicClassLoadingException: Failed to instantiate type AsyncAppender
        at ch.qos.logback.core.joran.spi.ActionException: ch.qos.logback.core.util.DynamicClassLoadingException: Failed to instantiate type AsyncAppender
...
Caused by: ch.qos.logback.core.util.DynamicClassLoadingException: Failed to instantiate type AsyncAppender
...
Caused by: java.lang.ClassNotFoundException: AsyncAppender

I removed logback.xml, but chat is still not working

Start by running the Java multi-room chat example and reproducing the failure after “join room,” then inspect the Play 2.7.3 setup and the reported logback.xml AsyncAppender crash. Done means the chat example works through joining a room; the issue also asks whether other examples need fixes, so their status should be checked.