PVRFormat.8bi. Any versions of Photoshop are not normal to be saved or opened. Pvr file will error
I had a go with the released version of the Photoshop plug-in and it turned out it was broken as you’ve said. The code hasn’t really changed for a long time but apparently the version of Photoshop we used for testing didn’t ever show a problem. I’ve recoded the entire plug-in for the next release which should fix the issues you’re currently seeing, but as it’s such a large change I’m unable to back port to the current release I’m afraid.
The next release should be out in the next few months - in the meantime you can either use PVRTexToolGUI or PVRTexTool CL as a workaround.