Error Messages

One more for you to work on. This was my initial problem, that the 'publish' button wouldn't work. Having tried it on my other laptop when I uploaded my image blip gave me an error message to say that my image was too small. I could then easily enlarge it and problem solved, but today the same thing happened. Luckily I could just enlarge it and got it published but why is that on one machine I get the error message and on the other one I don't. I'm using the same browser on both machines.

Being able to upload pics is pretty much the whole idea so is this my problem or yours? And if yours, can it be fixed please?