Basic Dictionary doesn't work when starting from Unity3D runtime

var dict = new Dictionary<string, string>()
{
	{ "aaa", "bbb" },
	{ "ccc", "ddd" },
};

result:

var dict = dict = new System.Collections.Generic.Dictionary`2[[System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]
{
};

Visual Studio 2017 Community
ObjectExporter 1.7.0
Runtime is started using the Unity3D engine (.NET 2.5)
What am I doing wrong?