I've now reverted back to Lightroom Classic CC 7.2 Everything is back to normal and very responsive. I've wasted untold hours fighting with the latest official 7.4 upgrade and trying everything possible to get it to work has been all for naught. More than 24 hours just updating all the presets I have is just ridiculous.It's truly sad that at this point I cannot go forward with my main catalogs which have upwards of 45,000 images in them. As new updates come out, hopefully with a fix, I may be able to continue with Lightroom but for the meantime I will stick with the older version but as I have no faith that there will be a fix anytime soon, I am now migrating all of my images to the stand-alone version of Capture One Pro which is by far infinitely faster and better in so many ways. If this is the way of the future with Lightroom Classic CC, I am not going to continue paying a subscription for software that cannot be updated. The fact that those who can't migrate to the newer updates miss out on things such as camera and lens profiles is also really just ridiculous. As a Lightroom instructor for the largest photography meetup group in Canada, I cannot teach a course on the new features of Lightroom nor will I now recommend this software to my students.