Syntax Error in plugin

I am running 4.1, which has introduced a bug from this plugin. I notice that all sorts of sites, all over the place, that use this plugin are experiencing this. Here is the error message I get on pages:
Warning: preg_match(): Delimiter must not be alphanumeric or backslash in /home/weglev/public_html/wp-content/plugins/who-hit-the-page-hit-counter/count_who_hit.php on line 430

I’ve looked at the code and cannot figure out what it wants, but I think that the /i modifier causes the i to be treated as a delimiter instead of a modifier. Not sure, but that’s my opinion.

https://www.ads-software.com/plugins/who-hit-the-page-hit-counter/