Error when computing confusion matrix in ArcGIS Pro 2.7.1

I have created a classified image and I am seeking to evaluate it using the following workflow:

1. Create Accuracy Assessment Points (tool)
2. Update Accuarcy Accessment Points (tool)
3. Compute Confusion Matrix (tool)

The workflow is demonstrated in this video: https://www.youtube.com/watch?v=-x1ipu5-7L8

When I try to generate a confusion matrix, I receive the following error:

Troubleshooting did not yield any answers so far.