TERA Shop uses Internet Explorer engine, you need to use legacy javascript. For the functions of _tera_client_proxy_ class to work, you also need to...
I have the same issue on the 100.02 64bit client while 92.03 32bit was OK, I think it's RAM related (check your PC RAM usage), when game hits the max...
if HSDN launcher uses the vanilla launcher, its fairly easy, how I did on my side was just to create a function that will modify the global variable...
They didn't ported their changes from EUR DC to the other, it's fairly easy to automate tbh (beside strsheets maybe, this one could require bit more...