You'll have to compare what you write with other HUBs. I've been lucky in that I've managed to avoid that particular comment. Good luck to you. Please don't be annoyed, but you also need to watch the way you use English. I'm a would-be copy editor and am quick to red pencil another's work. To be grammatically correct, you should have written: “I am stumped. Every time I try to make a HUB, it says ‘The content is not enough.’ Somebody help me.”
It’s always easier to find errors in someone else’s work. If you like, I’ll tell you a story about a regulation, a missing letter and my threatening to call the SPCA.