Message is not showing

-- url of the page with the problem -- : megaminds.uk.ht

Whenever a new coustmer is registered this message is usually shown:
Your account has been created and an activation link has been sent to the e-mail address you entered. Note that you must activate the account by clicking on the activation link in the e-mail that you receive before you can login.

But in my website when user submit the create account form, message is not showing only a blank page is showing.

Hi,

Please activate the debug mode in joomla in order to have the PHP error.
If you have a blank page it generally means that you have a PHP error which stop the rest of the page processing.
You can also check your PHP error log to have more details about the error.

Regards,

I turn on my Debug mode but still no error is shown.

Please also activate the "error reporting" option of the configuration and try again.If you still don't see any error, you will have to look in the PHP error log of your server for the error (if you don't know where to look, you can ask your hosting company support)

I have used a number of templates, what kind of error it is. please help me how do i show message there. IT only shows message on default joomla template, not on any other.
when i choose user activation to be none, neither self nor admin. it shows following error:
Warning: is_readable(): open_basedir restriction in effect. File(/dev/urandom) is not within the allowed path(s): (/home/u315439697:/usr/lib/php:/tmp) in /home/u315439697/public_html/libraries/phpass/PasswordHash.php on line 51

If you get a completely blank page, it means that it's a fatal error, not a warning. So that message is irrelevant to your problem and you should look in your PHP error log as I already said.

If you don't get a blank page but just that the main area of the template is blank, it means that your template is not displaying messages:
www.hikashop.com/support/documentation/6...tibility-issues.html

I don't get a completely blank page but just that the main area of the template where the message should be displayed is blank.
I will try the solution you have mentioned above.