I did an update on Lightroom CC 2015 and now Lightroom won't launch. Photoshop will not open .jpeg files, says it can't find them. It will only open PS documents.
I tried to delete the LR 5 Master Photos Catalog Previews.Irdata file but that didn't help.
I'm using Mac OS X 10.9.5, not sure if I need to upgrade my system to Sierra instead?
your os isn't compatible so i don't know how you got that installed. but because you did you could try resetting your preferences: https://helpx.adobe.com/lightroom/help/setting-preferences-lightroom.html
if that fails, uninstall your lr, update your os and then reinstall lr