[git] Git merge is not possible because I have unmerged files

The error message:

merge: remote/master - not something we can merge

is saying that Git doesn't recognize remote/master. This is probably because you don't have a "remote" named "remote". You have a "remote" named "origin".

Think of "remotes" as an alias for the url to your Git server. master is your locally checked-out version of the branch. origin/master is the latest version of master from your Git server that you have fetched (downloaded). A fetch is always safe because it will only update the "origin/x" version of your branches.

So, to get your master branch back in sync, first download the latest content from the git server:

git fetch

Then, perform the merge:

git merge origin/master

...But, perhaps the better approach would be:

git pull origin master

The pull command will do the fetch and merge for you in one step.