If the mechanism of extraClasspath is called, a token will be generated.
This token depends of the version of Tomcat in use (Token of Tomcat 8 is not the same of Tomcat 7).
But actually, if the web app is expanded and contains a META-INF/context.xml file, the token is generating in TomcatCopyingInstalledLocalDeployer without taking care of Tomcat version.
This cause a bug in Tomcat 8 because the token contains org.apache.catalina.loader.VirtualWebappLoader, which not exist in Tomcat 8 => ClassNotFoundException !
I will submit a github PR to fix this (this needs a little refactoring in the code)