Photoshop CC2018 issue on Macs
If you are on a Mac and using Photoshop CC2018, you need to change the PSD compatibility setting in Photoshop's Preferences to "Always". See screen grab below.
ProSelect uses Mac OSX to read PSD files and, in some cases, OSX seems to have issues reading PSD files if you don't have the Maximize PSD and PSB File Compatibility option selected when you save PSD files in Photoshop. When OSX can't read the file, the results can appear as an all-white image when the file is imported or updated in ProSelect.