guys, please suggest a way to debug

If all you did was update dependency versions, then one or more of those dependencies is going to be the problem. I would check out the last known commit that worked and check it still works, ensuring that nothing outside your project has changed (that you forgot about). Then just work through the commits until you find the dependency causing the problem (assuming you did nice fine grande commits).

You may also try a debugger: http://ohokgotit.blogspot.com/2013/05/debugging-running-clojure-application.html

Thanks