Hi Eric,
I purchased and installed version 3 as you suggested, but I'm still not operational.
For installation I did the following:
1) Downloaded version 3 of TubePress Pro and unzipped the contents which are now in the www/wordpress/wp-content/plugins/tubepress_pro_3_0_0 directory.
2) Downloaded shadowbox (version 3.0.3) and installed the contents of the shadowbox directory into tubepress_pro_3_0_0/sys/ui/static/players/shadowbox/lib/
3) Deactivated the old version of TubePress Pro and activated TubePress Pro 3 in Wordpress (I'm not sure that the activation ended cleanly because I got a blank white screen instead of returning to WordPress - I retried deactivating/activating several times with the same result - TubePress does show as activated in WordPress plugins screen)
I did not do anything with respect to keys and secrets as I didn't see anywhere to do this for WordPress users in the WP Admin/Settings/Tubepress/Feed area.
Can you please advise what I should be doing to get this to work?
Thanks