Hello 
where can I find unity log files? every time when I start my application (ie. game) the unity crashes.
Take a look at the Console. You can find it in
Applications > Utilities > Console
Unity messages should show up when you select either “All messages” or “system.log” from the log list.
There are also the logs from the Crash Reporter in ~/Library/Logs/CrashReporter
that could provide some info.
thx!