Nemosminer 3.3 - Unhandled exception error
Hi,

I get a couple of errors using version 3.3
![nemos 3 3 error](https://user-images.githubusercontent.com/25772604/45001028-f47e3800-afc9-11e8-8cf7-c1789c457f65.PNG)

This is the error I got recently. What can I do to solve this?
