I have recently updated my git (2.7.4.windows.1). Since then pulling from github produces output like this:
$ git pull --rebase
Fatal: TaskCanceledException enco
This error can also happen when your Git hoster is down, so check the status page (eg, GitHub status) to see if there is any incident on the hoster side before trying the other solutions here.
I just ran into this same problem and, in case it is missed in the comments for the accepted answer, the fix is:
git config --global credential.helper wincred
Credit to Hugo Allexis Cardona