I found a pretty confusing issue that seems Blocker to me.
In my project I am using a JNDI name to configure a piece of my application. Basically in this case Spring creates of Bean of type "java.lang.String". That was perfectly working under Tapestry 5.2.6.
Since I updated to 5.3-beta-19 1 time out of 3 the whole application if failling because Tapestry cannot resolve Page Name anymore.
After digging it turns out that Tapestry is Injecting the value of this Bean in several places where it should not : example applicationCharset or startPageName.
Please see attached screenshots for better understanding.