website 500 error but works on reload

I have a error that I work on for a wile now and I can't figure it out.
I work on a website called:
If I open the site in IE or an Incognito Window in Chrome I get a 500 Error in IE and a blank page in Chrome same in any mobile browser.
However, if I reload all loads fine. I can repeat this and it happens every time.

Some background:
initially I had the DNS for this domain on my own server but than I moved into GoDaddy DNS and forgot to remove the DNS entries in my BIND server. So I thought there maybe a  DNS issue. However I delete the DNS entries on my server on Saturday. Still it is happening.

Since this is a  wordpress site I naturally assumes it would be a cache issue. I saw there was SuperCache plugin on there. I deactivated it and removed the plug-in all together, including all cache related items in the config file. Still same issue. Strange is also that it even happens in the WP login page which is not really connected to an theme or plug-ins.

I checked the virtualhost entry in Apache and all looks file like all other domains.

I checked the htaccess file and it seems to be fine too.

So I am not 100% sure what else to check so I thought I would post here and see if anyone maybe had something similar and has some troubleshooting tips. I would be very happy to get some tips or maybe even a solution to this issue.

The system is running on lates wordpress, apache server, linux CentOS 6.7, PHP5.4

if you like to know anything else please ask me.

Thank you for assisting
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

You are having coding/setup issues.
Best bet is to look at te Apache logs(web server) /var/log/apache error.log should shed light on your issue
/var/log/messages /var/log/audit

Make sure all components on which the site relies, db server, web server etc is running without issues.

A 500 error points to an internal server error including being a issue with php outputting the wrong/incorrect data stream.....

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Jason C. LevineDon't talk to me.Commented:
Two easy things to check:

1) disable all plugins

2) switch to a different theme

Disable plugins, check, then switch themes of the problem persists. If either of those stop the white screen/server 500 from appearing on first load, you have your answer.  More info and additional troubleshooting steps here:
One gets a blank  page on a visit, a refresh seems to be possibly a redirection loop that hinders the processing.
The other possibility is you are using IP related test to make sure you are not being attacked, and that might be your issue. i.e. part of that mechanism the first page is blank, if it is a robot/search agent, they will go away, if it is a user, they will reload the page and will see what the page is.
Jason C. LevineDon't talk to me.Commented:
My guess is a corrupted WordPress-specific  .htaccess rule. Disabling the plugins will usually remove the offending rewrite and allow normal operation.  Re-enabling plugins might write the right rule again and allow normal operation.
ThomasPartnerAuthor Commented:

Thank you all for your tips and suggestions. All made sense but it narrowed down to a fail2ban issue on a specific rule that I had. maybe it was a bit too tight. It seems alli s fine now but I will monitor a bit.
The main clue was that another site reported the issue but this site did not use wordpress.

The main issue was the apache-myadmin rules in fail2ban. Thank you for the assitance and to be fair I split the points by 3.

Best wishes,
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Apache Web Server

From novice to tech pro — start learning today.