Github user conniey commented on the issue:
https://github.com/apache/lucenenet/pull/191
@NightOwl888
> Connie, do you think it is possible to utilize VS 2015 for development on
both .NET frameworks?
Yes, the .NET Core projects already build for both frameworks, so I was
hoping that the old csprojs and old solution could be removed/replaced in the
future. Then all development could be done using Visual Studio 2015. You can
switch between developing for different frameworks using the Navigation Bar in
VS2015.

> Secondly, I am getting some errors when building Lucene.Net.Portable.sln
using Visual Studio 2015 Community. Here is a screenshot. The issue appears to
stem from line 262 in C:\Program Files
(x86)\MSBuild\Microsoft\VisualStudio\v14.0\DotNet\Microsoft.DotNet.Common.Targets
on my machine.
Urgh. I used to get that error. I worked around it by running `dotnet
restore` on the directory first before opening Lucene.Net.Portable.sln in
Visual Studio. Would you mind sending me the `.vs\restore.dg` file when you
get that error?
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