Are you certain you're following the right steps?
1. Sign/Log in.
2. Place your cursor on "Discuss" at the top of the page.
3. Scroll straight down to "Knife Commerce".
4. Slide your cursor straight to your right and go up to "Knives for Sale or Trade".
5. Click on that.
6. Click the box on the top left that says "New Topic".
From there you type in the title, and then in the large box you type in the description, add your photos, then click on the "Submit" box.
FYI: After you're done adding photos, click on the "Preview" box first. Read it and make sure it's what you want, if it's good, click "Submit" and wait for the PM's to start coming in.