Runtime Error with Sculptris


i have a question on the program sculptris i keep getting a runtime error when i work on complex projects. is this a bug? how can i fix this? i know it is not my OS i have a brand new alienware product 2014/15 i recently have started working with 3D modeling and i love sculptris its a great quick sketch 3D modeling program. its so good i am actually contemplating purchasing the program zbrush. If this is what is to expect from zbrush/sculptris then i may not actually purchase the program. now correct me if i am wrong but this product is under beta testing if so then i am saying i might have found a bug.

help would be really appreciated to anyone who has this same problem or from any admin. who can help find a solution.

thank you and i hope that this doesn’t break the deal of a potential customer.