I posted this problem about a month ago. I have wasted several hours with an adobe tech from India doing everything there is to look at lightroom without actually considering that its a code problem and not an computer environment problem. He said he would get back to me and I never heard from him again. I have posted tests in forums, noted the details of the failed fix for the Mac version. Ben told to do the fix for the mac version when a tech couldn't bother to read the recent post about the fixes failure to work, and the detailed results of those test.
Adobe is using users like me to test their software bugs and can't seem to address problems of fix anything or even read the results of posts.
Are the techs that call on commission?
Is it possible to get a fix this decade?
Lightroom 6.4 what an update! It still locks up the slideshow module and video import won't work.
Congratulations on NOTHING FIXED. What has it been a year now?
ADOBE is unable to fix any problems again and again and again... WHAT WASTE!!!!
I'd start by looking at a problem with your computer. Personally I have never had LR hang in any module on any image. That is on both a Mac, several years ago, and on Windows from Version 1 of LR.