I just discovered and implemented this excellent plugin. It appears to function just fine as best I can tell.
However, I noticed an error page creeping into my stats:
#9999999 (loading title)
I suspected it was related to this plugin and indeed everytime I access subscription management from a post, it creates this in my stats (but I never actually observe an error page when using the plugin on posts).
I suspect this is related to the permalink structure in the settings.
Should I enter the permalink structure for a page or post in the plugin settings?