I know the line where its failing - were in the stacktrace. The question is why the container got null.
If you have a look at the other classes in the trace which are called before it should never reach the stack that deep but fail before with an error like there is no container. To me this look like you're overall setup is missing to correctly setup the TilesContainer with the ServletContext. Take a debugger and have a look why it would not fail on the first invocations of those tiles tags which checks for a non null container and who might remove it. kind regards
