Try re-installing the General Rolling Stock Dependencies pack under Steam/Transition Era -> Dependencies for the couplers. The second problem looks to be a problem with hardware accelerated texture compression, I would search the forum for info relating that. I haven't had that problem myself, I think Shane(shaneturner12) has a tutorial on how to fix it somewhere.
Seems crazy that it is YOU having this problem. Did you have those items before, or this is first time installing them? My only other guess would be, did you try to reskin either of those? Would be interesting to know. I hope the suggestion above fixes it, as it is frustrating with that. I had gone through four reinstalls, until I got it right. Seems that I had to do it in a certain order, and without installing an old version and patching up. Just download of the newest install files did that part nicely.
Could you update this when you got it fixed? I would think it could be beneficial.
It isn't suppose to mean anything, I am just stunned that you have a problem with it. Anyway, did you want to let the community know? Or, are you just not going to? Oh well...
Posted this yesterday in the Third Party Content forum yesterday but I'll add it here as well.
I had to do an extended database repair, and when it completed the kuid 103012:100313:1 showed up as faulty. This is the mesh library for the CN and B&O 55 ton hoppers. The error was that main.im could not be loaded. I deleted the faulty kuid, re-downloaded the 55 ton hopper cdp's and re-installed, but the mesh library is showing up as a missing dependency now.