this problem is sort out… add only one line and problem is resolved.
open “google-drive-wp-media.php” file and add the following line after this line(line no 2661):
Before:
@header (‘Cache-Control:public, max-age=31536000’);

After:
@header(‘HTTP/1.1 200 OK’);
@header (‘Cache-Control:public, max-age=31536000’);