I reinstalled p12 (12/22 update). I removed existing preferences. The document window and other palettes seem to float and dock appropriately. However, when I try to export an image, I get the same file with a black image which is only 10 kb where my other images are typically 150 kb. I don't think that I was having this problem before I installed the 12/22 update. I know that I have exported images successfully using p12. I also don't have this problem with p11.3 which I still have installed. I have a Dell XPS 8930 with an NVidia GeForce GTX 1050.