Need VS 2015 to open Project

I upgraded a project from 4.10 to 4.11.
The project is shared through version control.
I am the only one using VS. I recompiled everything and updated and committed the binaries.
However it no longer opens on systems that do not have VS installed.
How to get around this problem?
Previously this worked fine.

Removing the ‘Modules’ section from the .uproject file makes the editor no longer think it is a VS project.