I don’t know the direct cause of it, but It happened to me before on Amara. The skill tree would not display the images of the skills in the skill tree menu or on class mods. The first time, I had to verify my game files to get it to work again. Happened to me today when I booted up the game. Verifying now to see if it fixes it. Again, don’t know the direct cause but since it has happened for a second time, I feel like I should make it known or see if anyone else has had this problem on PC (Amara is the only one that has been affected so far for me personally).
Edit/Update: Verifying did fix the issue if this has happened to anyone else. Also, I play on Epic, not Steam.