Lightroom CC 2015 will become unresponsive and crash often when I am exporting and editing photos. This began fairly recently. I am on an iMac with great specs so it's not my computer. Adobe really needs to step up their game in Lightroom performance here, it's becoming absolutely absurd how slow everything is becoming in Lightroom.
Which version of MAC OS X are you using? See Lightroom and El Capitan | Mac OS 10.11 if using OS X 10.11
Uncheck "Use graphics Processor"
Let us know if that helps
Try Akash's tip first, but you will probably have to go back to Lightroom 2015.1.1 (see here for instructions: How do I roll back to Lightroom 2015.1.1 or Lightroom 6.1.1?). There are some real bugs in the latest Lightroom that especially manifest on El capitan, but also affect some people on Yosemite and on Windows that include hangups and crashes even when the GPU acceleration is turned off and the "Add photos screen" is turned off in Preferences->General. Your crash when exporting is very typical of that issue.
Thank you I will try both of these