I had a problem in a properties file but the framework never warned me.
The properties file was the default configured in struts.xml for i18n but the strings never appear and the log said that there were no key defined.
The problem was just a mismatch between a slash and a backslash in the properties file but I spent lot of time to track the problem (about 8 hours probing lot of stuffs).
I just see that the properties file was not in the ValueStack. Perhaps if struts can't push the content of the properties file in the ValueStack, it can put an advise in the log of the container.
I think that a framework like Struts must help developpers to find quicker the problems and in this case it's not helping.