I can not press the "submit update" button for my mod

So I have created a mod and submitted it to the steam workshop, but the button you can press to Submit Update the mod is greyed out, not in blue. This means that I cannot Submit Update my mod. Therefore, I wondered why cannot I “Submit Update” my mod?

I have added situations, simulations and a policy to the mod and stuff like that, and I have typed the name for the title, description and stuff like that, in the boxes that appear on the same place as where one submit ones mod. However, I am a little bad at modding so I have not added any icons to my situations/simulations/policies and that stuff. Can that be the reason for why I cannot “Submit Update” my mod?