I use the currently latest release of IR and US steam loco pack. When I place a PS4 or G-3 class engine, it places, but about a second later the game crashes. And when I reload the world, it crashes again. The crash screen refers to their obj.png files.
Is there any way to fix this? I really like the pack and there are many really useful engines. Even PS4 and G-3 are obviously quality models, there is just that nasty bug that crashes the game.
RAM should not be the issue. I have 16GB in total and 12GB allowed for MC.

Delete the cache folder from your instance directory, then relaunch.

Thanks, problem solved.
By the way, is there any chance to fix the issue with icons/thumbnails?

Do you have Optifine installed? If so, disable fast render, delete cache, and relaunch.

Thank you, this problem is now also solved.