Verify if the date, time, and time zone on your PC are correct.
Check the LAN settings:
Start Isabel 6 and try to login.
Verify if the websites of Isabel 6 and/or eGovernment websites are available in your list of Trusted Sites.
Make sure you have installed the latest security patches in Windows and verify the following settings in Internet Explorer:
If you see that the changes to these options are not taken into account or if you cannot modify these settings, please contact your System Administrator.
Verify the Internet Options > Connections > LAN settings. Copy all available information since this is required to connect to the internet.
After the reset of your browser, if you have copied some settings at the beginning of the procedure, you can now go back to LAN settings to restore them.
Verify if 'Automatically detect settings' is disabled.
Try to login to Isabel 6.
If the issue is not solved after performing all previous steps, contact Isabel Customer Care.