Possible solution if you receive the error message ‘Geen geldig certificaat’ (‘Not a valid certificate’) after clicking on the Login button at ‘Certificaat login’ (‘Certificate login’): Install the following 3 underlying certificates one after the other. This should change the certificate status to ‘Dit certificaat is in orde’ (‘This certificate is OK)’.

You can check the certificate status by selecting Tools / Internet Options / Content tab / Certificates (halfway down the page) / Personal tab / double-click on the valid TTP certificate / Certification path tab. You will see the certificate status at the bottom of the window. This will be OK once you have installed the three underlying certificates.

If this has not resolved the problem, or if you see a different error message, contact CIS.