Lightroom is Quitting Unexpectedly

Hi there,

I have been running Lightroom on my iMac (Macos Yosemite) for a while and its been great. I recently had to update to Macos High Sierra and after updating, Lightroom wont open - it keeps quitting unexpectedly. I dont want to uninstall it in fear of losing all of my presets. Please can someone assist.