One of our agents is reporting "Warning" in the group details, and no data is being synced.

However, access to logs is not possible, because a click on the "LOGS" option results in a few minutes of "loading" screen, and then a blank page.

Hi Christian,
 
You can use the following methods to check the log.

Check the Event Log entries on the box where you installed the SQL Data Sync Agent.

Event Viewer->Applications and Services Logs->SQL Azure Data Sync Preview or Event Viewer->Applications and Services Logs->Data Sync Service

Turning logging in verbose mode. Open LocalAgentHost.exe.config in notepad. This file should be present in your installation directory.

a) Uncomment the section that is currently commented < !-- < switches> < add name="SyncAgentTracer" value="4" /> < /switches> < trace autoflush="true" indentsize="4"> < listeners> < add name="myListener" type="Microsoft.SqlAzureDataSync.ClientLogging.DSSClientTraceListener, Microsoft.SqlAzureDataSync.ClientLogging, Version=2.0.0.0" initializeData="DSSAgentOutput.log" /> < remove name="Default" /> < /listeners> < /trace> -->

b) Stop and restart SQL Azure Data Sync Preview Windows Service. Now you would find the detailed logs in files named DSSAgentOutput*.log

There is a similar thread for your reference.
http://stackoverflow.com/questions/21297247/sql-data-sync-fails-and-no-logs-are-available


Thanks,
Lydia Zhang

If you have any feedback on our support, please click here.

Thank you, the extended log did show the problem, and we were able to solve it.