djlinden on "[Plugin: Wordfence Security] Wordfence 5.0.7 Scan not running when requested"

When I click the button to start a scan, nothing happens.
My error log contains the following line thereafter:
2014-05-12 10:38:11.764 [INFO] [69.46.36.8:37816-0#APVH_MyDomain.com] File not found [/home/tripz/public_html/403.shtml]

https://wordpress.org/plugins/wordfence/