Try another browser, and try clearing site cookies and the Ctrl +F5 reload. It is possible you have been blocked deliberatly or unintentionally from the forum, but then I would expect you to be able to see the forum, but not post. Please look at

• Firefox can't load websites but other browsers can
• Also consider Firefox and other browsers can't load websites

If problems persist Presumably the websites is using cloudfare. Contact the website or cloudfare about your problems.

• This is the cloudfare sites explanation of what it is
  https://support.cloudflare.com/hc/en-us/articles/205177068-Step-1-How-does-CloudFlare-work-
• CMP has a contact form on http://thecmp.org/contacts/ and also gives

Sales 
For government surplus rifles and ammunition, CMP products and CMP memorabilia.
Anniston Distribution Center
Civilian Marksmanship Program
1401 Commerce Blvd
Anniston, Alabama 36207
Telephone: (256) 835-8455
FAX: (256) 835-3527
E-mail: [email protected]

Programs 
For marksmanship training, competitions, National Matches, safety information and youth marksmanship
CMP Program Headquarters
P.O. Box 576 (mail)
Camp Perry Training Site, Bldg #3
Port Clinton, Ohio 43452
Telephone: (419) 635-2141
FAX: (419) 635-2802
E-mail: [email protected]</blockquote>

Thank you for your response. I tried cleaning out the cookies and cache, no cure. I tried using Internet Explorer, it also could not connect to www.forums.thecmp.org. I also tried using Firefox in safe mode, no go. I then refreshed Firefox, which didn't cure this problem, but instead led to more difficulties (see my other question).

I've tried contacting the CMP via email per your suggestion, got a reply that my inquiry had been forwarded, then nothing. I've also entered a question on the CloudFlare Support page, have gotten some responses, but no luck so far in a solution. The last response indicated I should explicitly white list the web address in question, but I don't know how to do this, cannot find either a white or black listing location or file. Any suggestion on how to do this? TIA!

If you are still having problems and it also affects other browsers but is only that specific site that is a problem then it is likely a problem with security software on your computer blocking the site, or the site itself blocking you.

What is the position with IE does that now load the site ok or not ? What security related software do you use ? Please give details including the Firewall, any Anti Virus (AV) software and any ad blockers or script blockers.

Look at any security related software and your firewall, remembering to check for cloudflare and the named problem site. The same goes for clearing cache & cookies. We do not know what security related software you are using, although you will presumably at least have a Firewall enabled.

• Configure firewalls so that Firefox can access the Internet
  • How to let Firefox use the internet on your Windows computer

I then refreshed Firefox, which didn't cure this problem, but instead led to more difficulties (see my other question).

• Firefox home page search and right click options not working. /questions/1072414