A dummy project to find bugs in the hackaday.io interface. I could upload images to the gallery but not add or edit files. Same with Chrome and Firefox, and on my mobile phone.
After making sure I had all the latest Linux updates, Richard Hogben's noticed there had been some recent updates and suggested of doing a hard refresh to clear the cache, which is control-shift-R on my Chrome browser. This fixed the problem. Note you have to do this for each page that plays up.

I am leaving this project up in case other people have the same problem and google for solutions.