So, was rendering images and including an alpha (tgalpha), and had sucessfully done this literally several dozen times.
Then got notification that maintenance had been applied to my PC and I would need to reboot. So I did, but prior to doing this I deleted all the regular images plus the companion TGalpha images from their default folders. Also saved the testing environement as a TGD, and assumed I would simply reboot computer, start Terragen and load the testing environment.
But after rebooting and restarting Terragen, I'm no longer to get alpha images (meaning no alpha images appear in the TGalpha folder.)
Been trying to fix this for a few hours but getting no where.
If anyone has any ideas about what's wrong here I would love to hear them!!