Hello everyone,
So earlier today I’ve made 2 different animations, assigned each one to their own Action Editor tab, pressed the little Shield Icon to determine ‘Fake User’… then I restart blender and see one of the models isn’t animating, I inspect the action editor and ALL OF THE KEYFRAMES are GONE - I even have the armature selected, in pose mode, ZERO keyframes. - While the other model still has all of the keyframes. the tab is still there with its custom name and the shield icon ticked, but ALL OF THE KEYFRAMES ARE GONE…
Please, I beg for help, I don’t want to keep animating this over and over again.
Cross your fingers, MMB in the timeline and drag downward.
Blender is brilliant at loosing keyframes up out of sight.
Just checked and it’s 100% not there, so far I’ve made 3 animations with their own action editor save, I’ve re-opened blender again and only the first animation that i’ve made stays saved consistently,
the other two sets of keyframes for the animations have been deleted again, the names & ticked "Fake User’ shields are still in the ‘Browse Action’ drop down menu… empty.
So try with a new file.
Do a couple of animations on the cube, fake user, save, open.
This is to check if your file is corrupt, or if blender has had a brainfart.
Have you checked the filter names box (Top left search box in dope sheet) to see if you accidentally typed something in there?
Triple check that the one you are opening is the same one you saved… Its so easy (for me 
) to accidentally save an animation into the shaders folder or something similar.
Hi, very strange behavior.
Are you using some sort of 3D Animation/Rigging Addon which changes the Rig? At least, hypothetically, if a Bone is destroyed in this process, in order for the Addon to achieve certain special task, the Bone’s Key Frames might be Deleted as well. For example, Rig on the Fly Addon can do radical changes to the Rig in the middle of 3D Animation, such as destroying Bones and then reconstructing them refreshed, in the case of its IK/FK Switch feature; though I do not know if such process actually Deletes the Key Frames, it might still serve as an analogy to what I mean regarding Addon features.
What about Baking the 3D Animation inside that Action? (I don’t think this will help much, but assuming it would be an Interpolation-related issue, this might be interesting).