Windows IoT installation OS version

Owlowish

Hello,
I want to run my UP board with windows 10 IoT core. I followed the guide available on the official Up site and downloaded the .ffu for UPboard on this page. Windows IoT core runs nicely after the installation.
The issue is, I want to develop an uwp application for my device using C++. When I try to deploy the program to the remote target via Visual Studio 2017, the IDE crashes every time (I've managed to deploy correctly with Rapsberry Pi though). So I decided to create manually a .appx file in order to install the app through Windows Device Portal. When I do so, I get the error that the .appx cannot be installed because it's OS' version is out of date (and I can't update it with device portal).
Have you guys ran in to similar issues ?

Thanks.