It could be that the Participation Type that they selected when they registered isn't configured to raise money. To verify that this Participation Type is configured to raise money, please follow the steps below:
  1. Go to Fundraising > Select TeamRaiser.
  2. Click Edit next to appropriate TeamRaiser.
  3. Go to step 7. Manage Participation Types.
  4. Click Edit next to the Participation Type in question.
  5. While on the first page a. Identify Type, go to option 5. Fundraising Enabled.
  6. Mark the checkbox next to "Yes, this participation type involves raising money."
  7. Click Next and your changes have been saved.