ethercard fail

"/Applications/Arduino.app/Contents/Java/tools-builder/ctags/5.8-arduino2/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns "/var/folders/8j/b__8wsps0jx30v4__zth01fw0000gn/T/build2c1ba46ac629ef65ee9319f3f44c912d.tmp/preproc/ctags_target.cpp"
"/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10606 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino" "-I/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/variants/standard" "-I/Users/james/Dropbox/Projects/Proper Larson/Arduino/libraries/ethercard-master" "/var/folders/8j/b__8wsps0jx30v4__zth01fw0000gn/T/build2c1ba46ac629ef65ee9319f3f44c912d.tmp/sketch/webClient.ino.cpp" -o "/var/folders/8j/b__8wsps0jx30v4__zth01fw0000gn/T/build2c1ba46ac629ef65ee9319f3f44c912d.tmp/sketch/webClient.ino.cpp.o"
/Users/james/Dropbox/Projects/Proper Larson/Arduino/libraries/ethercard-master/examples/webClient/webClient.ino: In function 'void my_callback(byte, word, word)':
webClient:15: error: 'void my_callback(byte, word, word)' was declared 'extern' and later 'static' [-fpermissive]
 static void my_callback (byte status, word off, word len) {
                                                         ^
webClient:15: error: previous declaration of 'void my_callback(byte, word, word)' [-fpermissive]
 static void my_callback (byte status, word off, word len) {
      ^
Using library ethercard-master in folder: /Users/james/Dropbox/Projects/Proper Larson/Arduino/libraries/ethercard-master (legacy)
exit status 1
'void my_callback(byte, word, word)' was declared 'extern' and later 'static' [-fpermissive]