how to make the article / blog with pictures, while I experienced it always error when uploading a picture following article.
May be there will be some connection error at your end. Try again to do so. Better luck for the next turn.
If you have not any issue in your Internet Connection, then please read carefully more about the criteria for making blog. May be there will be difference in the format of your attached pic and the required pic format.
@shirish is right you should retry this process otherwise you should contact to the admin.