i installed AX 2012 R3, then i installed R3 CU8 update with offline package.
the problem is after installed, the version number is different.

although it was running well on the first heavy test, i’m afraid the R2 crash issue because different build number will raise again at R3.
to make it same , install AX R3 with slipstream CU8 package update, here is the full guide from MSDN blog :
http://blogs.msdn.com/b/axsupport/archive/2015/04/21/how-to-slip-stream-ax-2012-r3-cu-8.aspx