ActiveSMS write errors to the system's Application log. You can access the application log as follows:
1. Goto Start Menu->Settings->Control Panel
2. Double-click on 'Administrative Tools'
3. Double-click on 'Event Viewer'
4. Select 'Application Log' in the Event Viewer.
5. Look for the most recent errors from 'ActiveSMSServer'
6. Double-click on the 'ActiveSMSServer' error, please copy and paste the Description into an email back to us.