arduino refusing to compile

I’m trying to compile code onto my Arduino Mega 2560, but it’s not working. The weird bit is that this happened all of a sudden, as I was compiling code just this morning.

Here is the error message:

Arduino: 1.6.10 (Windows 10), Board: "Arduino Mega ADK"

C:\Users\Ben\AppData\Local\Temp\ccRtNWoc.ltrans0.ltrans.o: In function `main':

ccRtNWoc.ltrans0.o:(.text.startup+0xe0): undefined reference to `setup'

collect2.exe: error: ld returned 1 exit status

exit status 1
Error compiling for board Arduino Mega ADK.

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


Please post your code that causes this error using code tags(</> button on the toolbar). If it’s longer than the forum allows then attach the file. If it uses any 3rd party libraries then post the link to where they can be downloaded or if they’re installed via Library Manager then state the full library name.