Is it necessary to enable PID for the heat bed? (2 replies)

I'm trying to upload the new marlin firmware to my board but I'm getting an error:-




Arduino: 1.8.5 (Windows 7), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

sketch\Marlin_main.cpp: In function 'void gcode_M304()':

Marlin_main.cpp:8930: error: 'scalePID_i' was not declared in this scope

if (parser.seen('I')) thermalManager.bedKi = scalePID_i(parser.value_float());

^

Marlin_main.cpp:8931: error: 'scalePID_d' was not declared in this scope

if (parser.seen('D')) thermalManager.bedKd = scalePID_d(parser.value_float());

^

In file included from sketch\Marlin.h:46:0,

from sketch\Marlin_main.cpp:244:

Marlin_main.cpp:8937: error: 'unscalePID_i' was not declared in this scope

SERIAL_ECHOPAIR(" i:", unscalePID_i(thermalManager.bedKi));

^

sketch\serial.h:52:76: note: in definition of macro 'SERIAL_PROTOCOLPAIR'

#define SERIAL_PROTOCOLPAIR(name, value) (serial_echopair_P(PSTR(name),(value)))

^

sketch\Marlin_main.cpp:8937:5: note: in expansion of macro 'SERIAL_ECHOPAIR'

SERIAL_ECHOPAIR(" i:", unscalePID_i(thermalManager.bedKi));

^

Marlin_main.cpp:8938: error: 'unscalePID_d' was not declared in this scope

SERIAL_ECHOLNPAIR(" d:", unscalePID_d(thermalManager.bedKd));

^

sketch\serial.h:52:76: note: in definition of macro 'SERIAL_PROTOCOLPAIR'

#define SERIAL_PROTOCOLPAIR(name, value) (serial_echopair_P(PSTR(name),(value)))

^

sketch\serial.h:61:40: note: in expansion of macro 'SERIAL_PROTOCOLLNPAIR'

#define SERIAL_ECHOLNPAIR(name, value) SERIAL_PROTOCOLLNPAIR(name, value)

^

sketch\Marlin_main.cpp:8938:5: note: in expansion of macro 'SERIAL_ECHOLNPAIR'

SERIAL_ECHOLNPAIR(" d:", unscalePID_d(thermalManager.bedKd));

^

exit status 1
'scalePID_i' was not declared in this scope

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

if I comment out the "PID BEDTEMP" statement this error doesn't come.....
So is it really important for the PID on the heat bed to be on
(P.S. I don't know how to solve the error :S , so I'll be asking over here if I have to.)