Import member error-log?

I use the advanced import tool to migrate my existing member administration to my new website. But unfortunately I loose a lot of information during this import, and I don’t know why… Is there any log I can check?

If you want help on this, you are going to need to set out EXACTLY what you have done for each step. Otherwise, we’ll all just be guessing.

I will challenge the support desk, because I have several issues with this import