Log view presents live stream of application log. Portions of log that correspond to error conditions failures are colored in red.
You can pause log refreshing by clicking Pause link located below the log text area.
Application log
You can also find all the logs in The log is also written to tfs-jira-synchronizer\AppData\log\tfssync.log* files folder inside your webserver web server root folder (typically: c:\inetpub\wwwroot).