Update your Flash please (yes it can be updated and your more than a security risk. Flash Player Version: 27.0.0.183 https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, Win IE . . . .) Note: Other software is offered in the download. <Windows Only>

Update your Video Card drivers driverDate: 8-25-2010 to last version available in 2012 https://www.intel.com/content/www/us/en/support/products/81507/graphics-drivers/legacy-graphics/graphics-drivers-for-mobile-intel-4-series-express-chipset-family.html

Update Firefox to 52.4.1 No enhancements just security updates. https://www.mozilla.org/en-US/firefox/organizations/all/

Do these things and might not have that issue.

Please let us know if this solved your issue or if need further assistance.

If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block (wanted) content (e.g. Adblock Plus, NoScript, Ghostery, uBlock Origin) always make sure such extensions do not block (wanted) content.

• make sure your extensions and filters are updated to the latest version

You can try these steps in case of issues with web pages:

You can reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

• hold down the Shift key and left-click the Reload button
• press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
• press "Command + Shift + R" (Mac)

Clear the cache and remove the cookies from websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Clear the cache:

• Options/Preferences -> Privacy & Security -> Cached Web Content: "Clear Now"

"Remove the cookies" from websites that cause problems.

• Options/Preferences -> Privacy & Security -> "Use custom settings for history" -> Cookies: "Show Cookies"

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

mcelmoyl said

when I click contact when looking at an add on craigslist it it says I am not a rebot and does not give me the contact information.s

Have you tried checking the box next to 'I am not a robot'  ?

That's all it should take.

In the header of your post you're asking why   you are getting this -
Please see : https://www.craigslist.org/about/help/captcha

and also : https://support.google.com/websearch/answer/86640?hl=en