no more data read from socket error with triggers
This Error can happen with PL/SQL and came up with ORA-600 [kqlidchg0],ORA-00001 and/or ORA-01578 see MOS Doc ID 17210525.8. 

For 12.1 and 11.2 install latest Patch (April 2016)

ORA-600 [kqlidchg0] with PL/SQL

ORA-00001: unique constraint (SYS.I_PLSCOPE_SIG_IDENTIFIER$) violated

Try:

ALTER SESSION SET PLSCOPE_SETTINGS = 'IDENTIFIERS:NONE';