Just a heads-up about another plugin that risks interference with WPPA+.
I've got WPPA+ 4.9.0 installed, and also another plugin called WP Publication Archive 2.5.3: http://jumping-duck.com/wordpress/plugins/wp-publication-archive/
My latest round of plugin updates failed and partially crashed my WP site because both plugins declare a function called wppa_activate(). I've renamed the function in WP Publication Archive to wppa2_activate() on my WP site for now, which temporarily resolves the clash, but it will reoccur with the next update if the function names between these plugins aren't deconflicted. There may be other functions in both plugins that are at risk of future naming conflicts.
Thought I'd best let you know, as these two plugins abbreviate identically! I'll also let the devs on WP Publication Archive know about WPPA+.
Regards, Ian Chennell