Can't push git, visual studio. Git failed with a fatal error. fatal: HttpRequestException encountered

Cause: GitHub updated their security requirements on the server side. They no longer support TLS 1.0 and 1.1, only 1.2. Older Git Credential Manager for Windows versions used 1.0.

Solution: Update Git for Windows. Version 2.14.3 and newer include an up-to-date Git Credential Manager for Windows.

Alternatively you can update only the Git Credential Manager for Windows itself. It supports TLS 1.2 from version 1.14.0 onwards.

Simply update your Visual Studio to the latest version and this should be fixed. Worked for me.

Git Credential Manager for Windows v1.17.1 fixes the issue on BitBucket. Note the one comment:

Bug Fixes:

Fixes a bug related to Bitbucket authentication (thanks to @Foda for contributing the fixes).

https://github.com/Microsoft/Git-Credential-Manager-for-Windows/releases