Hello,
Please follow ALL of his instructions :
You should use a custom field of the type "text" in order to enter your URL
I suppose that you change the type but I also know that you did not change the content of the custom field ; so you still have some non working data as Nicolas explained you :
The "link" type has both the name and the link saved together in the database and thus if you use that data directly in your href, it won't work like you can see.
So, please read carefully messages and explanations that we're giving you.
Regards,