I have OLP 2.1.2 on my church's laptop, running OS X 10.9.5 and I've been encountering some crashes when saving services.
Today I downloaded OLP 2.1.3 to my own computer running OS X 10.10.3 and those crashes aren't occurring - YAY!
What do I need to do to upgrade the church's laptop to the latest version, and will I lose songs and slides and other media which has already been created?
I haven't upgraded to 2.1.3 and I don't use OS X but all previous upgrades on my Windows machines have preserved my complete OpenLP setup (all my songs, bibles, custom slides, themes, keyboard shortcuts...). I've done an upgrade just before a service and everything worked seamlessly (I'm not suggesting you do that). Only the window layout seemed to be lost. The OpenLP installer should offer to create a backup of your data files but you could also do this manually.