I was just about to go search how to post payment proof when I read this. I've done it successfully in the past, but don't remember how to go about it. I know it always took me a few hours to figure it out. I don't remember ever getting an error message, but don't think I got my payment the last time I tried, either. I'm sure I did something wrong. It's a challenge for me to figure out the process, but I am ready to give it another try.