What does these error messages means?

What could these mean?

In file included from C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h:13:0,

                 from C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\Dhcp.cpp:4:

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h: In static member function 'static byte SPIClass::transfer(byte)':

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:56:3: error: 'SPDR' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:57:12: error: 'SPSR' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:57:23: error: 'SPIF' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:57:27: error: '_BV' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h: In static member function 'static void SPIClass::attachInterrupt()':

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:63:3: error: 'SPCR' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:63:15: error: 'SPIE' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:63:19: error: '_BV' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h: In static member function 'static void SPIClass::detachInterrupt()':

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:67:3: error: 'SPCR' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:67:16: error: 'SPIE' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/SPI.h:67:20: error: '_BV' was not declared in this scope

In file included from C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\Dhcp.cpp:4:0:

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h: In static member function 'static void W5100Class::initSS()':

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h:349:25: error: 'PinDescription' has no member named 'pPort'

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h:349:65: error: 'portModeRegister' was not declared in this scope

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h:349:70: error: 'PinDescription' has no member named 'ulPin'

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h: In static member function 'static void W5100Class::setSS()':

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h:352:8: error: 'PinDescription' has no member named 'pPort'

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h:352:73: error: 'PinDescription' has no member named 'ulPin'

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h: In static member function 'static void W5100Class::resetSS()':

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h:355:8: error: 'PinDescription' has no member named 'pPort'

C:\Users\GustavoFring\Documents\Arduino\libraries\IoTkit\utility/w5100.h:355:72: error: 'PinDescription' has no member named 'ulPin'

Does this mean?

That you've possibly got the wrong processor selected.

Those registers are ATmega SPI control and status registers - perhaps you have a Due or other non-ATmega board selected? The _BV is more worrying, that's from Arduino.h I believe which suggests the IoTkit library isn't #including it?