Fatal error triggered by inet_pton()

Hello,
I started to see occasional fatal error on multiple sites. Here is the trace debug:

inet_pton(): Argument #1 ($ip) must not contain any null bytes /wp-content/plugins/wordfence/lib/wfUtils.php:927 
Stack trace:
#0 /wp-content/plugins/wordfence/lib/wfUtils.php(927): inet_pton()
#1 /wp-content/plugins/wordfence/lib/wfCrawl.php(25): wfUtils::inet_pton()
#2 /wp-content/plugins/wordfence/lib/wfCrawl.php(139): wfCrawl::verifyCrawlerPTR()
#3 /wp-content/plugins/wordfence/lib/wordfenceClass.php(2439): wfCrawl::isVerifiedGoogleCrawler()
#4 /wp-includes/class-wp-hook.php(341): wordfence::veryFirstAction()
#5 /wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters()
#6 /wp-includes/plugin.php(522): WP_Hook->do_action()
#7 /wp-settings.php(593): do_action()
#8 /wp-config.php(113): require_once('/home/****/p...')
#9 /wp-load.php(50): require_once('/home/****/p...')
#10 /wp-blog-header.php(13): require_once('/home/****/p...')
#11 /index.php(17): require('/home/****/p...')
#12 {main}

SERVER: REQUEST_URI => /wordpress/ 
REQUEST_METHOD => GET 
REMOTE_ADDR => 34.143.189.51 
HTTP_USER_AGENT => Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

Thank you!

Jaro