I have seen a few of the following error in the error log:
Unable to verify the referrer address. Please go back and try again
I figured they were being caused by bots trying to register until it happened to me! I'm in OK using my phone hot-spot and got this error when I tried to log in. I posted about it on the SMF forum and they offered a tweak I will implement once I get back but they provided a workaround.
If I attach to the site by entering "
https://www.bmwr65.org" I get the error. If connecting by leaving off the WWW I log in properly. Folks can do this until I can address the root cause which was introduced when I did some redirection stuff to fix the security issues Chrome complained about.
I hate computers...