Just updated to Sierra and recorded to audio. Trying to export either track or region causes Logic 9.18 to quit. Yes, I've sent a message to Apple.
This has happened in more than one file and this is bad news.
Phoned Apple and found that Logic 9 was probably incompatible with Sierra so, at great length and with help, I've now upgraded to Logic X. so will go to that forum after I figure out how to use the new software.