Arduplane firmware unable to upload

Hello please help!!
i tried to upload arduplane firmware on pix hawk board, earlier firmware flashed successfully, but now i suddenly started getting error
{
Build failed
→ task in ‘bin/arduplane’ failed (exit status 1):
{task 140536835528336: upload_fw arduplane.apj → }
(run with -v to display more information)

}
help required| , thanks