Error messages in Rider IDE when adding hangfire.aspnetcore to project

As soon as I add the Hangfire.AspNetCore nuget package to my aspnet core application (1.1.2) I get errormessages on several types like “Cannot convert source type ‘string [System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]’ to target type string [System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]”

Any idea how to solve this?