Runes of Magic US / AU

Someone doesn't want you to visit them. Most of the time stuff like this can be resolved by just logging out then back in, but on occasion when that doesn't work I will defrag my hard drive. Now after that I will run a check for spyware and malware. If and only if those do not work you might check your video driver to be sure it is up to date. If it is the last thing to do is to open your computer case (if it is a desktop), and using dust-off blow out the dust bunnies occupying your heatsinks.
Unfortunately crashes are inevetible with RoM most likely due to bad programing, bad connections, or even the weather (solar flares are notorious for causing problems with eletronics). Worst area for crashing has got to be Thunderhoof Hills. I constantly crash there when I go there which is not often anymore.

Quoted from "Murkalael;528120"

And I forgot to mention the bug of flying monster, probably a known issue as well. when you're in an area for too long, bored of killing the same mob over and over, and then you need just 1 item from that mob. So you place yourself in a higher area and kill a mob bellow, if it dies running towards you it'll be in the middle of the air where you can't reach the loot >.<

That one is surprisingly easy to deal with, annoying though it may be. Stand under the floating corpse, position your pointer just below it, then jump and click on the mob when the pointer changes to a hand. Takes a bit of practice, but it can be done fairly easily.

Or, if you have a pet (egg pet, not a Warden pet) and a Pet Perfume enabled, the pet will loot the mob for you.

Oddly enough, RW had fixed the "unreachable mob" problem back in Chapter II or III, but the bug snuck back in awhile back.

As for your rendering issue, a relog usually takes care of it. If not, then yes, maybe your video driver could use an update.