This utterly confused me for a while, so I'm posting it here. If you ever run ATG 7.0 and find that you are getting a very strange error message (something like "Cannot access method getPriority") in the ACC, then you are using the wrong JVM. 05 has some issue with reflection.

Use the JVM provided with ATG (i.e. comment out the JAVA_VM environment variable) and it should work fine.