edit Captcha Sniper.ini
file at C:\Users\UserName\AppData\Roaming\GSA Search Engine Ranker\captcha_service\Captcha Sniper.ini
change the the [captcha_result] variable to be:
[captcha_result] back=\n
PLEASE NOTE: The default settings for Captcha Sniper should be used when using it with GSA. You should also not select any captchas or captcha types in the user interface.