[seshagiric]

it is likely the email id you are trying to use is already taken up. If you scroll up a bit, there may a error mark near the email field (I had this issue and but was trying to change the captcha).

[knz]

The first couple of times I tried the error message wasn't even being shown, but when I changed the username it worked.

[yesimahuman]

That did happen initially but then it only complained about the captcha