I have a model which is animated which I dragged the animation file over the the viewport. When I click play it will animate the character in the viewport window in a loop just as I need. But when I click “play as standalone” it is stuck in the T-pose. I have searched everywhere and cannot get this thing to animate in a standalone build. I don’t need anything special with it, I just need it to start playing just as does in the viewport when I press play. I am using the first person template. Any ideas?
I figured it out by right clicking the animation file, renaming it because it was a long strange name then choosing save. (there was an asterisk in the thumbnail preview originally and it kept giving me an error that it could not save) I am not sure if this was a bug. Hope this helps someone.
I had the same problem and saving the file individually by right-clicking in the content browser worked. Weird.
Thanks for sharing this solution @haggler2. This worked for me as well.
Thank you very much for posting this was having the same prob in 4.12 
Thank you very much for posting this was having the same prob in 4.12