Just imported the same files to Capture One Pro 11.2.0 with no problems. C1Pro quickly created previews and I was able to adjust them immediately. Lightroom Classic CC 7.4 is still spinning "Loading". This now been over 40 minutes of downtime! Maybe a decision is being made for me? Use the program that works!
We're sorry to hear about this, let us help make this right. As Lightroom is not able to build previews, could you please try resetting the preferences of Lightroom and let us know if it helps with the issue?
Preferences Reset Lightroom - https://helpx.adobe.com/lightroom/help/setting-preferences-lightroom.html
Also, does updating to Lightroom version 7.5 help?
Restarting for a second time Lightroom has stopped the "Loading" loop. So I am back in business.
As for updating to 7.5, the last several updates have been so problematic I am choosing to wait and see. I really can not afford the downtime associated with software bugs.
Thanks for your input though!