This issue occurs when someone has commited the code to develop/master and latest code has not been rebased from develop/master and you're trying to overwrite new changes to develop/master branch
Solution:
- Take a backup if you're working on feature branch and switch to master/develop branch by doing git checkout develop/master
- Do git pull
- You will get changes and merge conflicts occur when you have made changes in the same file which has not been rebased from develop/master
- Resolve the conflicts if it occurs and do git push,this should work