Could this be a configuration issue? A network port closed which should be open perhaps?

The client side exception doesnít tell me much. Iím not sure if the reindex did just take too long. There might be more information in the server logs though.

The reindex is launched through the webstart admin client. We think the reindex is needed because the daily backup failed last night.

If you did run the backup via ConsistencyCheckTask, it should have written a report to the backup directory. Could you check this to see if there are any errors reported?  It is important to know if more severe problems were detected. A reindex alone might not be sufficient.