Column to predict combo box is unpopulated after uploading yelp dataset

**System Information (please complete the following information):**
- Model Builder Version (available in Manage Extensions dialog):
- Visual Studio Version

**Describe the bug**
- On which step of the process did you run into an issue:
- Clear description of the problem:

**To Reproduce**
Steps to reproduce the behavior:
Download and Add Data step of ML.net tutorial

**Expected behavior**
Expected dropdown to have col0 and col1 options

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Additional context**
Add any other context about the problem here.