gmail does not work in firefox anymore

gmail no longer works in firefox. Nightly has been giving me a message about clearing cache and cookies for many many many months. After I do that, nothing changes and I still end up in a website about clearing cache and cookies. Firefox ESR is not able to delete gmail emails after I check the delete box. It says they are deleted but the don't ever go away. I cannot find any version of firefox that works with gmail. Please let me know if you have found one and provide a link for me to download that version. thanks