CCS: communication line rs485 A-B line 10 ohm resister failer

Tool/software: Code Composer Studio

Part Number:TM4C1294NCPDT

Tool/software: TI C/C++ Compiler(CCS 6.3)

1.         Controller                            : TM4C1294NCPDT
2.         Make                                   : Texas Instruments
3.        modbus                               :  RS485 (75176A IC)
4.        level shifter                         :  17221A
   
5.        issue facing                          : Burn 10 ohm resister(R89,R87)
   
6.  

At present we are  facing issue for burn 10 ohm resistor in our RS485 communication line or A-B line.

we are connecting  above 32 devices in our communication line .I updated image and marked block color.if any corrections available in our design plz inform.

please help to solve  this problem.