There are lot's of possibilities, including: (1) an automatic update to your browser changed some settings, (2) an auto-update to your security software changed some settings, (3) your internet service provider has new restrictions on file transfers, (4) you have reached some unknown limit for photo storage on the banana.org server, (5) there is an unknown error on bananas.org server settings that is randomly affecting some users.
I sympathize with your frustration. Personally, I'm not having trouble uploading images:
