Turbulent Viscosity Ratio Warning Message

Why am I getting a turbulent viscosity ratio warning message in the console when running a case?

The message you are seeing is more a warning than an error. It stipulates that the ratio of turbulent viscosity over the laminar viscosity is larger than 1e5 (default). While this is not an error per-say, it is usually unphysical to have such a high ratio (note that this ratio limit is defined in Solve-> Controls -> Limits). The ratio becomes very high in regions of high turbulence, where the grid is (in most cases) too coarse. In many case, the message occurs at the beginning of a simulation and will disappear as the simulation converges.

For more details, refer to this document.