My mesh keep says it has thousands of zero length edges

So I have made my architecture concept model by doing sweep2 and when I do meshcheck it says it has something like 7000zero length edges… I anyway have ignored it and exported to .STL but some parts are not even shown when trying to get 3d printed…

Hello - please post a screen shot of the mesh settings you are using. Post a file with the object as well if you like.