I create a new git repository with the help of bitbucket called confusionmatrix. Now, I'm trying in another git repository (called workspace) add the confusionmatrix repository as submodule like this:

git submodule add https://....@bitbucket.org/..../confusionmatrix.git

But I'm getting the following error:

'confusionmatrix' does not have a commit checked out

I already made this with other git repositories to the same repository "workspace" and worked well.

What I'm doing wrong?