ORA-00600 [kqlnrc_1] most of the times is about an invalid object in the Library Cache of the database.
An Oracle Trace file is always generated during the time of this error. Below provided are few of the steps that you can try atleast before you passon the case to Oracle Support team.

Open the trace file with an editor (The following lines are from an 11.2.0.3 trace file) :

1. Find the first ORA_600 error argument
ORA-00600: internal error code, arguments: [kqlnrc_1], [0x143C6DAD0], [], [], [], [], [], [], [], [], [], []

2. Search the trace file for 0x143c6dad0 (its the first argument in lower case):

DDE: Problem Key ‘ORA 600 [kqlnrc_1]’ was flood controlled (0x2) (incident: 35561)
ORA-00600: internal error code, arguments: [kqlnrc_1], [0x143C6DAD0], [], [], [], [], [], [], [], [], [], []

LibraryHandle:  Address=0x143c6dad0 Hash=cd3b674a LockMode=S PinMode=S LoadLockMode=0 Status=INVL
ObjectName:  Name=PUBLIC.TEST
FullHashValue=5c820441b24ce2df1d9a0971cd3b674a Namespace=TABLE/PROCEDURE(01) Type=SYNONYM(05) Identifier=0 OwnerIdn=2147483644
Statistics:  InvalidationCount=2 ExecutionCount=0 LoadCount=1 ActiveLocks=1 TotalLockCount=6 TotalPinCount=6
Counters:  BrokenCount=1 RevocablePointer=1 KeepDependency=0 BucketInUse=6 HandleInUse=6 HandleReferenceCount=0
Concurrency:  DependencyMutex=0x143c6db80(0, 8, 0, 0) Mutex=0x143c6dc00(233, 45, 0, 6)
Flags=REM/PIN/TIM/[00022801]
WaitersLists:
Lock=0x143c6db60[0x143c6db60,0x143c6db60]
Pin=0x143c6db40[0x143c6db40,0x143c6db40]
LoadLock=0x143c6dbb8[0x143c6dbb8,0x143c6dbb8]
Timestamp:  Current=04-25-2013 09:41:24
HandleReference:  Address=0x143c6dc90 Handle=(nil) Flags=[00]
ReferenceList:
Reference:  Address=0x145badf28 Handle=0x12d7be980 Flags=DEP[01]
Timestamp=04-25-2013 09:41:24 InvalidatedFrom=0
LibraryObject:  Address=0x10dbe40b0 HeapMask=0000-0001-0001-0000 Flags=EXS/LOC[0004] Flags2=[0000] PublicFlags=[0000]
DataBlocks:
Block:  #=’0′ name=KGLH0^cd3b674a pins=0 Change=NONE
Heap=0x12297cc10 Pointer=0x10dbe4150 Extent=0x10dbe4030 Flags=I/-/P/A/-/-
FreedLocation=0 Alloc=0.257812 Size=4.000000 LoadTime=15174108210

3. Find the object :

SELECT object_name,object_type,owner,status
FROM dba_objects
WHERE object_name=’TEST’ and owner=’PUBLIC’;

OBJECT_NAME OBJECT_TYPE OWNER STATUS
————– ————- —————- ——-
TEST SYNONYM PUBLIC VALID
4. Compile the synonym owned by public.

As sys :

SQL> alter public synonym TEST compile;

or Recreate it

SQL> create or replace public synonym xyz for xyz@javadb@testlab;

And That’s Fixed,

Hope That Helps
Prashant Dixit