I\'ve just created a new project in ASP 5 MVC 6 beta8 and a compatible class library for tests. The problem occurs in this new \"Web Class Library\" project that I intended
You can't have two different versions in the same project. You can use a * to allow up- or downgrade. See this artical Dependency-Resolution
Update: This can now be fixed by upgrading to AutoFixture.AutoMoq 3.41.0 or later.
Original Answer:
In the targets section of project.lock.json capitalize "moq", so that the AutoMoq element looks like this:
"AutoFixture.AutoMoq/3.38.0": {
"type": "package",
"dependencies": {
"autofixture": "3.38.0",
"Moq": "4.1.1308.2120"
},
Unfortunately, you will have to do this again every time the lock file is regenerated.