That's interesting. I'm glad you were able to get it working, but I'm not sure what may have changed when restarting the process. If there are no log messages, it is unlikely that GTAC would have enough information to investigate and provide a root cause.
I should mention that EXOS 15.3 reached End-of-Engineering in February of this year, and will reach End-of-Support in Feb 2016. You may want to begin planning an upgrade 🙂