Why is there a yellow triangle in HTTPS?

Question

Computer networks

It says it's because of the content. Decided to find this content. Deleted everything from body, left one word. It's still the same icon. How to be?
And here's another question. I created the crt files manually, because where the certificate was ordered, keys and certificate codes (and not ready-made files) were sent to the letter. Maybe I didn't put it in right?

Answer 1

It was in the .htaccess settings

Answer 2

What exactly was wrong with the settings?