I Am able to make a new emblem but when I try to upload it as the new emblem it doesn't. I have tried signing out and back in but the problem doesn't go away.
My Lt Commander had created a new clan emblem and experienced what you are. He had saved it ,of course, and continued to try and upload over a couple of days- we could see it on our "phone aps",just not on the Ipads or tablets. 3 days later it showed up. Like matuzz indicated, server issues come and go quite often ,so, please be persistent, you will get it! Good luck