Problems with weapon holding animations

I have some problems with movement animations. I've used mixamo's rifle movement animations as a base, only altering them inside mixamo (as far as I remember). Part of them work well enough, like this one screencaptured while strafing (Left hand displaced intentionally for better viewing):


However, in at least three of the animations (idle, forward and backward running) the left hand is a mess, with fingers rotating upwards over joint limits (seems like it is reversed for some reason):


The animations also look wrong with unity preview model. I didn't notice anything special in the animations with a quick glance in blender, they seem pretty much like the functioning animations.

I've checked my character rigging, T-pose seems fine, only thing I noticed was fingertips were rotated down:

With rotations like:

I tried zeroing the rotations, with no luck in fixing it. Any ideas where the problem could be and how to fix it? The character has been imported from Makehuman in T-pose with game rig, no self-made adjustments. I'm not super skilled in animation-related things in Unity. I'd be happy if I could just make/force a general non-twisted grip for the left hand, as the game is a top-down game where the animations don't have to be super accurate.

 

My only experience with mixamo is horrible. Try bringing one of their models into blender and all hell breaks loose. Like flying spaghetti monster what the hell happened to this guy... I think it's intentional to try and "protect" their assets. But I'm no animator, just my experience with mixamo. Hope someone has a real answer.

 

While the animations seem to differ slightly in the previews, I think they are one of the best animations assets I've found around for free. I have no experience of the 3D characters though.

 

As long as you use them as is they're great ye. I tried to tweak like it sounds you are though and it was a ridiculous mess. Tough when you're restricted to free though.

 

This appears to be the problem. Are the fingers mis-aligned before bringing into Unity?

Is the proper avatar definition applied from the character onto the animations?

 

I can't spot it in blender, the character is in a normal T-Pose with fingers in normal T-pose position. I've checked other animations and the fingertips are rotated in all animations in, so this definetly seems to be the problem. I could get a decent animation with only the fingertips being off (thumbs are rotated unnaturally):


I'm not sure I understand the second question correctly, so I will describe what I've done,hopefully it answers your question. I have imported the animations separately into unity (part, like the idle animation mentioned are from different 3d-models, most/all of them have the same makehuman game rig though if it makes a difference), configured the rig to be humanoid, made some root transform adjustments and then simply selected them as a part of the character's animation blend tree. As I said, I'm not a animation specialist - Is this a bad workflow?
Edit: I re-imported the character straight from MakeHuman to unity, and it seems to work now. I suppose I had altered something in blender unintentionally.