Lucee 5 Illegal class format error

Hi All

I have been using compiled classes in production servers, this worked fine
in previous versions of Lucee i.e 4.5. When testing version 5 I get this

Lucee Error (java.lang.ClassFormatError)
Message java.lang.ClassFormatError
Extended Info failed to load template

this works fine with uncompiled code but not compiled class files when the
filename is renamed to match the original cfc name, anyone else having such
strange issues