Error blank check

[MINHLE]

MY PROGRAM FOR THE 16F877A


adcon1 = 7


TRISD = 0 ; set port D as output

LOOP:

PORTD.0 = 1 ; let pin 0 HIGH

PAUSE 300

PORTD.0 = 0 ; LET PIN 0 LOW
PAUSE 300

GOTO LOOP

AFTER ERASING THE PIC; THE ERROR IS STILL THERE :ERROR BLANK CHECK AT 0000;

sometime i could program this this error, sometime program was aborted;
however, nothing work at all
the beginning of the program is right?