If you uninstall the okta cli, I suggest you remove the "okta.yaml" file that may have been generated in a ".okta" directory on you PC before your reinstall. On my PC that was located at "C:\Users\myname\.okta".

I've never used the okta cli before so I just gave it a try and I was able to create an app. Here are the steps I performed.

1. Downloaded the cli for Windows from "https://github.com/okta/okta-cli/releases" and placed the okta.exe found in the zip file in C:\okta\okta.exe
2. I did not need a new Okta test tenant so I did not run "okta register" instead I ran "okta login" and then it asked me for my Okta Organization and I typed "https://myoktatenanturl".
3. It then asked me for an Okta API token so I went in to the Admin site of that Okta tenant in my browser and generated one. See https://bit.ly/get-okta-api-token for details on how to generate a token. Once I had the token I copied and pasted it into the cli cmd window where it had prompted me for it and pressed enter key.
4. I then typed "okta apps" in the Okta cli and a list of all my apps on that Okta tenant were returned along with their GUIDS.
5. Lastly I typed "okta start" in the Okta cli. It then showed me 14 app type options. I selected #6 (React + Okta) assuming that is what you would have tried. It then asked me which authorization server I wanted to use. We have more than one but you might just have one so it may not prompt you. I entered #1 for first one in my list of auth servers and then it ran and created a SPA app in my Okta tenant called "okta-react-sample" and created a new folder in the same directory as the okta.exe cli named "okta-react-sample" that has all all the code files. The file ".okta.env" has my auth server URL and the client id of the app.