I had both Nav 2015/2016 on my PC. I uninstall Nav 2016 setup, yet all the server instances which I have created in Nav 2016 version is still appear in Nav 2015 MMC. Simply I tried to remove the Nav instance which I had created in Nav 2016 version using Nav 2015 MMC. It was not possible and the following error prompted. Also I tried by removing both 2015/2016 versions and reinstalled Nav 2015 version. But still the instance that I created in Nav 2016 is appearing in Nav 2015 MMC. 
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