Every time I merge a branch back into my master branch, I can no longer push to origin. I get the message fatal: master cannot be resolved to branch
I m
Could it be that you write Master instead of master? If the system is case sensitive they wouldn't match, and lower-case master is the default in most repositories.
Another issue might be this with your workflow:
Created a new branch git branch TestBranch
With the command above, you create a branch, but do not switch to it.
I believe you should checkout manually by git checkout TestBranch
or create the branch with checkout and create it by git checkout -b TestBranch
.