Activated this plugin, configured as a black list, and blocked four locations. Then logged out. When attempting to login, login form is never displayed, instead, users see a white screen.
I was able to duplicate this on several different servers.
Only one entry in error log ever seems to appear. Below are two examples, each from a different server:
[12-Dec-2013 05:03:30 UTC] PHP Fatal error: error traversing database - perhaps it is corrupt? in /home/xxxxxxxx/public_html/wp-content/plugins/limit-login-countries/vendor/geoip/geoip.inc on line 613
[12-Dec-2013 05:18:42 UTC] PHP Fatal error: error traversing database - perhaps it is corrupt? in /home/xxxxxxx/public_html/wp-content/plugins/limit-login-countries/vendor/geoip/geoip.inc on line 613
Note: Database on each site I tried is not corrupt. Remove the plugin (by deleting the directory via FTP), then everything works.