During git rebase origin/development
the following error message is shown from Git:
fatal: refusing to merge unrelated histories
Error redoing m
Two possibilities when this can happen -
You have cloned a project and, somehow, the .git directory got deleted or corrupted. This leads Git to be unaware of your local history and will, therefore, cause it to throw this error when you try to push to or pull from the remote repository.
You have created a new repository, added a few commits to it, and now you are trying to pull from a remote repository that already has some commits of its own. Git will also throw the error in this case, since it has no idea how the two projects are related.
SOLUTION
git pull origin master --allow-unrelated-histories
Ref - https://www.educative.io/edpresso/the-fatal-refusing-to-merge-unrelated-histories-git-error