An old thread, this one, but I think it's solved. I ran into the same problem - tapestry refused to start complaining about missing keys e. g. org.apache.tapestry.template-encoding.
The old workaround, to define the missing keys in e. g. the Application file solves the problem. Also: In my case the root cause was my SymbolSource which was based on a ResourceBundle. The ResourceBundle.getString method throws an exception if the key is missing, whereas a SymbolSource should return null for a missing key. Catching the exception in the SymbolSource seems to fix everything OK (besides the obviously bad error message from Tapestry). --Alec
