Playing on a SnapShot server, issues not present on local play, game will load and play and consistently crash, but at random intervals. Sometimes it seems like there is a relation to chunk loading (if traveling long distances) sometimes it seems there is no correlation.

Crashes output a crashlog in the MacOS, but occasionally (rarely) in the minecraft launcher. Including latest crash report from the Apple Crash Notifier.

I have re-installed Minecraft/Launcher from scratch. tried using the built-in JavaRE, same issues.

I have even Reinstalled the Mac OS to see if it was OS specific.

the last bit of output from the minecraft launcher is:

[11:27:13] [Client thread/ERROR]: Item entity 67447 has no item?!
[11:30:00] [Client thread/ERROR]: Item entity 76925 has no item?!
[11:35:12] [Client thread/ERROR]: Item entity 99362 has no item?!
[11:36:09] [Client thread/ERROR]: Item entity 103524 has no item?!
[11:40:17] [Client thread/INFO]: [CHAT] You can only sleep at night
[11:41:02] [Client thread/ERROR]: Item entity 135235 has no item?!
[11:41:53] [Client thread/WARN]: Received passengers for unknown entity

Got a dump from the launcher, Notable are the final lines:
[11:44:08 ERROR]: Game ended with bad state (exit code 134)
[11:44:08 INFO]: Ignoring visibility rule and showing launcher due to a game crash
[11:44:08 INFO]: Deleting /Users/jabackes/Library/Application Support/minecraft/versions/1.9-pre2/1.9-pre2-natives-1124232251667943