Hi there.
Sorry to hear that you are having issues with the Invites add-on. What version of AffiliateWP are you using? And do you have any other AffiliateWP add-ons active? If so, have you tried deactivating all other AffiliateWP add-ons except for Invites? And have you tried deactivating all other plugins except for those two?
Also, you said that the error occurs during install/activation of the plugin. Do you see any error messages related to invites?
And just for future reference, please post to the Plugin Support Forum for the plugin you need support on. This allows us to keep track of your issue and respond much faster.