Thank you for your answers. If you take a look at the Project Members, what is your Role?
Also, do you know if you authenticated with your user/pass or with a token?
Did you try to create a branch from the web then create a new file from the web and commit this new file?
Just to be sure. Is it a self hosted instance of CE? Did you look at the server logs?
Thanks for your answers. I have been in contact with GitLab support, and they have finally fixed the bug. They did not give me the real reason why I had this error … Seems to be from multiple reasons, or a specific action that had been done at a specific time. Well that’s fixed and that’s the most important.