I'm using Inventor Pro 2014 for FEA. I have problem on meshing, it says that internal error in the mesher.
How can i solve it...? here attached picture of the said problem.
Without more information there's no guarantee that I'm giving you the right solution here, but it LOOKS to me like you've got geometry problems with the model that you're trying to test. If you're using welds, it's not uncommon for several weld beads to intersect in odd ways that look like an octopus that Picasso painted in collaboration with Dali, and this can give you errors like that. Similarly, if you've got highly non-planar faces, or odd intersections / corner geometry that can do it as well.
Post up your model, let's take a look and see what we can see. I only have 2013 at the office, but when I get home (10 or so more hours) I'll be able to look at it. Someone else may be able to get to it quicker, though.