If you never enter the processFolders method then I guess the exception already occurs while obtaining the folders from Exchange (the connector.getRootFolders()
call which is a call to the library used to connect to Exchange).
It's impossible to say what's wrong here though. That log seems odd, is this the Log entity in the ExchangeClient module? You should also see a log line in your console, does it tell you anything else?
Edit: the log is from incorrectly implemented custom code, replace the e.getStackTrace() call by e.getMessage() and figure out what's wrong when you have the actual exception message.