reprot_max_skew command issue

When I use timing_quest GUI to reprot_max_skew, the tool display "Nothing to report"?

But if i report_skew -from Node1 -to Node2, The tool still running even a lot of time (about >100 hour) has passed. I don't konw what's problem about this command.

PS: My veriosn is QuartusII V10.0, linux 64 version