The term "linear workflow" (lwf) deals with the Gamma correction in 3ds Max and V-Ray. By default Max settings, the colour management is set to non-linear, as the Gamma correction in the Max preferences is not enabled - it is also called "non-linear workflow". If the colour management is set to linear by adjusting some Max and V-Ray settings, it is called "linear workflow".
All amberspice compilations include 3ds Max models which are materialized for non-linear workflow based settings, as well as specially materialized models for linear workflow based settings. If you are not familiar with the term "linear workflow", or if you deliberately turn off the gamma correction in 3ds Max, please use the Max files in the folder "non_linear_workflow". In the case where you use linear workflow, the Max files in the folder "linear_workflow" are the correct ones.