I keep getting this error message on Hands-on challenge.

It's bit frustrating, because I've double checked everything.

Create an opportunity with the Opportunity Name = '500 units' - Done
Stage = Prospecting - Done
with any Amount and any Close Date in the future - Done 
Pick any value for the Account Name - Done
Add yourself to the opportunity team for the '500 units' opportunity with the Team Role of 'Sales Rep'. - Done and done.

Would anybody be so kind (and smarter than me) to help me with this problem?

I keep getting this error message on Hands-on challenge.

It's bit frustrating, because I've double checked everything.

Create an opportunity with the Opportunity Name = '500 units' - Done
Stage = Prospecting - Done
with any Amount and any Close Date in the future - Done 
Pick any value for the Account Name - Done
Add yourself to the opportunity team for the '500 units' opportunity with the Team Role of 'Sales Rep'. - Done and done.

Would anybody be so kind (and smarter than me) to help me with this problem?