I got a very simple website without any link or something else. I created a self-signed certificate. (link to create self-signed certificate). After this I added it to my site in the IIS (link to add the self-signed certificate to IIS site). My Problem is now that my site is still not secure (local). Chrome, Firefox and IE are not accept my certificate. When I look if my certificate is valid: It's valid.
Can Anyone tell me why it's still not secure and how to fix it?