I installed this last night, and I use 3.6.2 and it works perfect.
Thank you.
I read all the posts on this, and seen there was some questions by others that wasn't really answered correctly.
This is what I did.
1) upload manageActivation.php to the forums/includes/cron folder
2) in my control panel I added this product product-uam3_sabret00the.xml
3) I setup a cron job, "varname" was an issue, see my pic
4) turn on this plugin, see pic
I hope this helps