java.lang.NoClassDefFoundError after upgrade to v5.5

The error:
==> app/confluence/test/run/logs/catalina.out <==
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/juli/logging/LogFactory
at org.apache.catalina.startup.Bootstrap.<clinit>(Bootstrap.java:60)
Caused by: java.lang.ClassNotFoundException: org.apache.juli.logging.LogFactory
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)

we're still in our testing period, but since v5.5 came out, we skipped the 5.4.4 upgrade to move directly to the 5.5 release.
Our upgrade is fully automated, which doesn't give any issue on installing v5.4.4 and any former release, but I keep getting this error.

I already found that this error is generated because of a faulty zip-file, but after redownloading it 3x it still doesn't change a thing.