duplicate of [/questions/1081778] though it should have been the other way as Fred responded to other thread instead. When I go to the site https://www.openmailbox.org/#register, there is a captcha that should be displayed below TOS. In my version 40.0 of Firefox for the Mac sha 512 84228c5e70b0ca4b3a8444007691a06cac1ecb6d81995d11a225e6e29dac6799267ebfe60488d0934e32567599c6a4ef0f849dfddbbfd3abdf0b0282599f10c3 When I use Firefox Android it displays the captcha. This appears to be a problem with the Mac version of Firefox. I have removed all plugins, removed the profile, refresh Firefox.