Just upgraded to Pro. Install of Pro went fine. Then installed Photo Tagging. Then installed Instagram: Received the following error during activation:
"Warning: Cannot modify header information - headers already sent by (output started at *****/wp-content/plugins/rtmedia-pro/app/main/widgets/RTMediaGalleryWidget.php:236) in *****/wp-includes/pluggable.php on line 875"
Getting the same error now when trying to access admin section. Front end seems to be fine, though I havent tried to use any of the add-ons yet.