I completed the migration (skipping customer and order data for now) and followed the installation instructions carefully -- re-saving attributes, reindexing, etc. I can access admin but the frontend is showing an error. I checked the table and cannot see that this category id is duplicated. This is urgent so a fast response would be appreciated!
I used this migration tool on a fresh installation of Magento 2.1.1 -- no sample data or anything else was installed
(Exception): Item (Magento\Catalog\Model\Category\Interceptor) with the same ID "1185" already exists.
My apology for not clarifying early enough that our migration tool is currently available for Magento 2.1.0. The Magento 2.1.1 has just been released, so we need a bit more time for compatibility testing with this new 2.1.1 version.
Could you please try to proceed with Magento 2.1.0 again? I see this unexpected circumstance takes you extra time for re-migration. I am terribly sorry for such inconvenience.
If the issue still persists, kindly provide via private message or our email info (at) ubertheme.com the SSH and admin credentials of your site, we will help you out.
Thanks for your understanding.