CAC Troubleshooting

CAC Authentication Error

Unable to authenticate using your CAC card. Only DoD CAC cards can be used to access this site.

Troubleshooting Steps

  1. Please check that your CAC card is inserted and you are selecting the correct profile.
  2. In order to log in with your CAC Card, please close your browser and all tabs associated with it to try again.
  3. Try using a different browser

 If you continue to have NPS website website access and/or CAC authentication issues, please email: and include: 

  • Approximate time of your last access attempt, 
  • browser(s) you are using, 
  • network you are connected to, e,g, NMCI, MCEN, etc., 
  • any error messages you have received (screenshots are very helpful), 
  • your public IP address (to get your public IP address type "what is my ip" into Google or use this link: 

Issues on NMCI/MCEN  Networks

If you are able to get to the non CAC authenticated portion of the site, but you are not getting the prompt to select your CAC card or are seeing an error like "Bad Request", then you are probably being blocked by the DISA break and inspect. To get an exception added for a website on DISA break and inspect:

  1. Get the site domain ( and IP address ( and that you are trying to access
  2. Get your public IP address by searching on Google "What is my ip" or use this link:
  3. Call 614-692-0032 => Opt 2 (Infrastructure), then Opt 1 (Network)
  4. Tell them that you can access the website, but the CAC authentication is not working for you and you need a bypass for break and inspect. They will create a ticket for allowing access to the site from your network and will have you test access.