Runtime Errors only on certain characters

[854141_1452550234]

I am having a strange problem. I have a couple lvl 50 characters I can log into just fine and play. I have a couple other newer ones that are lvl 20-30s that whenever I get past entering the PIN on log in and while the game is loading up I get a Runtime Error C++ the application has asked the runtime to terminate it in an unusual way.  I can actually ignore the warning box without checking it and play quite a while before the game crashes.
 

This game has never been very stable (put mildly) and its why I have spent only small money on it. I get occasional client crashes in dungeons or loading screens and very occasionally a runtime error but never like this. I looked to see if there was a client side profile file or something so I could compare the older toons to the newer ones and discover sometime amiss but am not finding something like that.
 

The PC is older but has no problems at all with any other games or programs. I tried adding more runtime distributables etc. or other fixes but so far no joy. Any ideas how to proceed would be appreciated.