Running this command doesn't work anymore:

> db.runCommand(

)
{
"errmsg" : "exception: best guess plan requested, but scan and order required",
"code" : 13284,
"ok" : false
}

Log:

Tue Jun 1 11:11:58 connection accepted from 127.0.0.1:53690 #2
Tue Jun 1 11:12:14 Assertion: 13284:best guess plan requested, but scan and order required
0x812efdd 0x827f03e 0x82c97fb 0x82d10bb 0x82c0433 0x82c1003 0x81a8c59 0x81aaeaf 0x8254395 0x82e8912 0x811a0df 0x16bc1d 0x13380e 0xb1c8de
./mongod(_ZN5mongo11msgassertedEiPKc+0x29d) [0x812efdd]
./mongod(_ZNK5mongo12QueryPlanSet12getBestGuessEv+0x9e) [0x827f03e]
./mongod(ZN5mongo15bestGuessCursorEPKcRKNS_7BSONObjES4+0x19b) [0x82c97fb]
./mongod(_ZN5mongo10CmdFileMD53runERKSsRNS_7BSONObjERSsRNS_14BSONObjBuilderEb+0x36b) [0x82d10bb]
./mongod(_ZN5mongo11execCommandEPNS_7CommandERNS_6ClientEiPKcRNS_7BSONObjERNS_14BSONObjBuilderEb+0x2d3) [0x82c0433]
./mongod(_ZN5mongo12_runCommandsEPKcRNS_7BSONObjERNS_10BufBuilderERNS_14BSONObjBuilderEbi+0x323) [0x82c1003]
./mongod(_ZN5mongo11runCommandsEPKcRNS_7BSONObjERNS_5CurOpERNS_10BufBuilderERNS_14BSONObjBuilderEbi+0x49) [0x81a8c59]
./mongod(ZN5mongo8runQueryERNS_7MessageERNS_12QueryMessageERNS_5CurOpES1+0xc3f) [0x81aaeaf]
./mongod(_ZN5mongo16assembleResponseERNS_7MessageERNS_10DbResponseERKNS_8SockAddrE+0x10e5) [0x8254395]
./mongod(_ZN5mongo10connThreadEv+0x2e2) [0x82e8912]
./mongod(_ZN5boost6detail11thread_dataIPFvvEE3runEv+0xf) [0x811a0df]
/usr/lib/libboost_thread-mt.so.1.38.0(thread_proxy+0x5d) [0x16bc1d]
/lib/tls/i686/cmov/libpthread.so.0 [0x13380e]
/lib/tls/i686/cmov/libc.so.6(clone+0x5e) [0xb1c8de]