Hmm... Can't find: NSSQLiteStoreType Ah, perhaps it can't find it because I have CoreData listed as a Framework? Relating to that other problem I had? Ok, removing that from the project. Hmm... Still can't find it. Well, replacing that with "SQLite" since macirb can load it fine. Cool! Got all the way to a crash! vm_insnhelper.c:1017 if (RCLASS_IV_TBL(klass) && It's calling the selector "openAllWindows" on my AppDelegate class. #0 0x002b4ad7 in vm_eval (th=0x1013c70, initial=0) at vm_insnhelper.c: 1017 #1 0x002b6ffc in vm_eval_body (th=0x1013c70) at vm.c:1149 #2 0x002b8354 in vm_call0 (th=0x1013c70, klass=30150960, recv=27896416, id=164240, oid=0, argc=0, argv=0xbfffd970, body=0x1ac74e0, nosuper=0) at vm.c:443 #3 0x001eae22 in rb_call0 (klass=30150960, recv=27896416, mid=164240, argc=0, argv=0xbfffd970, scope=1, self=16893792) at eval.c:1471 #4 0x001eb069 in rb_call (klass=<value temporarily unavailable, due to optimizations>, recv=<value temporarily unavailable, due to optimizations>, mid=<value temporarily unavailable, due to optimizations>, argc=0, argv=0x0, scope=0) at eval.c:1487 #5 0x001ef42f in rb_apply (recv=27896416, mid=164240, args=22183376) at eval.c:1499 #6 0x002c5442 in rb_ruby_to_objc_closure_handler (cif=0xb015660, resp=0xbfffdad0, args=0xbfffda90, userdata=0x1ac74e0) at objc.m:1162 #7 0x9462a424 in ffi_closure_SYSV () #8 0x92de1fce in __NSFireDelayedPerform () #9 0x95f33b5e in CFRunLoopRunSpecific () #10 0x95f33d18 in CFRunLoopRunInMode () #11 0x93d006a0 in RunCurrentEventLoopInMode () #12 0x93d004b9 in ReceiveNextEventCommon () #13 0x93d0032d in BlockUntilNextEventMatchingListInMode () #14 0x968aa7d9 in _DPSNextEvent () #15 0x968aa08e in -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] () #16 0x968a30c5 in -[NSApplication run] () #17 0x9687030a in NSApplicationMain () #18 0x9462a1dd in .LCFI1 () #19 0x9462a771 in ffi_call () #20 0x002c4b60 in bs_function_dispatch (argc=2, argv=0x600050, recv=16893792) at objc.m:1562 #21 0x002aa125 in call_cfunc (func=0x2c48e0 <bs_function_dispatch>, recv=16893792, len=<value temporarily unavailable, due to optimizations>, argc=2, argv=0x600050) at vm_insnhelper.c:280 #22 0x002b7b50 in vm_call_method (th=0x1013c70, cfp=0x67ff88, num=2, blockptr=0x1, flag=2145, id=10813, mn=0x15fe000, recv=16893792, klass=16893824) at vm_insnhelper.c:370 #23 0x002b14b3 in vm_eval (th=0x1013c70, initial=0) at insns.def:1085 #24 0x002b6ffc in vm_eval_body (th=0x1013c70) at vm.c:1149 #25 0x002b72d1 in rb_iseq_eval (iseqval=17513136) at vm.c:1358 #26 0x001e7d6a in ruby_exec_node (n=0x10b3750, file=0x10b1f11 "/Users/ pierce/svnProjects/build/Debug/Frictionless.app/Contents/Resources/ rb_main-mr.rb") at eval.c:237 #27 0x001ed79f in ruby_run_node (n=0x10b3750) at eval.c:265 #28 0x002c24cb in macruby_main (path=0x31474 "rb_main-mr.rb", argc=3, argv=0x40e940) at objc.m:2613 #29 0x00002561 in main (argc=1, argv=0xbffff790) at /Users/pierce/ svnProjects/Frictionless/RubyFrictionless/main-mr.m:13 Current language: auto; currently objective-c It's pretty repeatable. You can download it from http://www.twinforces.com/Frictionless_MR.zip Pierce