If you have no access to license server, you will receive a following message:
No connection to license server.
Also there is a problem using JRE 6 updates 1 to 3. If you are using JRE 6 make sure you have at least update 4. It may be necessary to uninstall older updates.
If you have JRE 6 updates 1-3 or other unexpected error occurs, you will receive a following message: