Does Acrobat Reader open the PDF better?
I have the exact same thing. I tried updating and reinstalling photoshop, didn't work. It opens fine in Acrobat and Indesign.
No clue what is causing this and there seems no info on how to fix it. Hope someone can help.
What file format, can you post meaningful screenshots, can you provide a file, …?
Please read this (in particular the section titled "Supply pertinent information for quicker answers"):
What have you done for trouble-shooting so far?
Restoring Preferences after making sure all customized presets like Actions, Patterns, Brushes etc. have been saved might be a good starting point: