Has failed to upload due to an error: Please Help

I’m trying to upload a picture to my blog and I keep getting this message

“as failed to upload due to an error
The uploaded file exceeds the upload_max_filesize directive in php.ini.”

I still have a lot of space remaining. It happened to my last post but I just kept trying until it just worked. Now it gives me this message every time. My pictures are only 72 res and aren’t that huge so I don’t understand what is wrong