I downloaded the mendix studio pro 8.18.8 in laptop and for sign in, I am not able to the fields available. Even If it seen, not able to edit that. So kindly help me get over this issue. The above image represents my issue.
If the issue still persists, Disable any VPN or Antivirus or Firewall in your system and see if it works also try a different network, is this the same for all modeler versions? Do let us know.