I have been trying to create a new ad for about 3 days and when I look at the ad, it says that it is

I have been trying to create a new ad for about 3 days and when I look at the ad, it says that it is expired. I am doing nothing different from any other time that I have created ads before so I am wondering what the problem is. Also, why does it constantly ask you to put in a ˝category˝ when there is no way to enter anything in that field?