mkdocs: mkdocs start error following pages exist in the docs directory, but are not included in the "nav" configuration:

I get the following error when I start mkdocs. Now this works fine on one computer and not another. One computer I am running python 3.5.1 and one I am running 3.7.4. I think that is the only difference.

This is the error

mkdocs serve
INFO    -  Building documentation...
INFO    -  Cleaning site directory
INFO    -  The following pages exist in the docs directory, but are not included in the "nav" configuration:
  - index.md
  - management.md
  - tech.md
WARNING -  A relative path to 'docs/index.md' is included in the 'nav' configuration, which is not found in the documentation files
WARNING -  A relative path to 'docs/tech.md' is included in the 'nav' configuration, which is not found in the documentation files
[I 191002 17:30:02 server:296] Serving on http://127.0.0.1:8000
[I 191002 17:30:02 handlers:62] Start watching changes
[I 191002 17:30:02 handlers:64] Start detecting changes
[I 191002 17:30:05 handlers:135] Browser Connected: http://localhost:8000/
[I 191002 17:30:06 handlers:135] Browser Connected: http://localhost:8000/

this is what my .yml file looks like

site_name: Interview

nav:
- HR: 'docs/index.md'
- TECH: 'docs/tech.md'
- Management: '/docs/management'

Again, this is working on one computer. I tried to uninstall phyton 3.7 and install the same as I have on my other computer but 3.5.1 have been superseded and I couldn’t seem to get an exe file for it pip version 19.2.3 on both computers

So when I go to localhost:8000 the first page shows up “index”, but if I go to the nav on the page and click the HR item, I get a 404, all of the nav items I get a 404.

Thanks for any help