White preview with a PSD

PROBLEM

Why are my PSD previews white in Capture One?

SOLUTION

This is due to the PSD being saved without 'Maximize Compatibility' enabled in Photoshop's save process. When saving a layered PSD, be sure to enabled this option:

If you don't get this prompt, enable it in Photoshop's Preferences -> File Handling -> File Compatibility as noted in the dialog.