Single-custom not working

Hello, really nice template, why single-?.php not working?

Even template/content-?.php not working.

I’ve read some things on Google but nothing helped.

Can you help me?

Please detail your process a bit more so someone can help you. Also see this section of the blog post:

Hey, for me just reflush rewrite rules worked. Sorry to bother.

Again, really nice work here.

Glad you got it resolved.