Hi Joop!
Kindly try these suggestions:
1. Do a Repair of Little Math:
http://support.brillkids.com/entries/20433732-How-to-Repair-your-BrillKids-Learning-System2. If you are using an old version, please update to the new version (v2.1.660):
http://support.brillkids.com/entries/21432889-How-to-update-your-Little-Math-software-to-the-latest-version3. If you did #1 and #2 but you're still having problems, do a Repair of your .NET Framework:
http://support.brillkids.com/entries/20432481-How-to-Repair-your-Microsoft-NET-FrameworkIf you tried all the suggestions above and Little Math still hangs or you're getting an error message, please create a diagnostic report and send it to us directly from your Support Tools window or as an email attachment to support[at]brillkids[dot]com.
How to Create a Diagnostic Report
http://support.brillkids.com/entries/20438423-how-to-create-a-diagnostic-report-for-your-brillkids-learning-systemI hope this helps!