When I imported a Gambit mesh into Fluent, it gave me a error:Error: FLUENT received a fatal signal (SEGMENTATION VIOLATION). Error Object: () The mesh can not be displayed completely, and i cann't go on working. Could you give me a complanation about the question and how to solve it?, thanks a lot!

is your choice of solver OK?

the solver is FLuent5/6.the problem had been solved by reducing the number of mesh cell(from 80,000 to 30,000).But i don't know why?

Well, if you have to reduce, that must mean your grid is too dense for that particular mesh and Fluent had problems processing it. There's no need to cram up your grid cells in the areas that are not sensitive to your measurements i.e. surfaces you don't care about investigating. You can vary the grid density according to your investigation requirement.