This video shows how to remove nested git repositories, or submodules as they are sometimes called. We occasionally accidentally nest Git repositories. This mistake causes various errors to occur. It turns out you can fix it by typing:
git rm --cached MyNestedRepo
Watch this video for the details.
Please note that this video is not about removing intentionally nested submodules. I'm just addressing the case where you accidentally, and probably unknowingly, created nested repos.