If clearing your cache/removing cookies doesn't work as explained by @yangciou, I would recommend reaching out to private support with the name and link of the repository you are working with. They should be able to take a closer look.
Mark helpful posts with Accept as Solution to help other users locate important info. Don't forget to give Kudos for great content!
It happened to me too. What i understand is you need to clear the cache of your browser. I try on other browser it is working fine. Please clear cache and try hope it works....