The Frequency-dependent refractive indices check box has been renamed to Allow frequency distributions at release features.Expressions involving the ray frequency must always be included within the noenv() operator. Some expressions for user-defined refractive indices may fail to be evaluated properly in version 5.2a unless this operator is applied.In version 5.0, if the ray intensity is computed, the option to add Thin Dielectric Film nodes to a Material Discontinuity node is always available. In version 5.2a, the Thin Dielectric Film subnode can only be added if Add layers to surface or Add layers to surface, repeating is selected from the Thin dielectric films on boundary list in the Material Discontinuity settings window. If a model created in version 5.0 is opened in version 5.2a, and any Thin Dielectric Film nodes have been added, then Add layers to surface is selected from the Thin dielectric films on boundary list instead of the default None.The Retardance of the Circular Wave Retarder now indicates the rotation angle of the polarization ellipse of a ray that passes through the device. In version 5.0, the retardance corresponds to half of this rotation angle. The behavior of the Circular Wave Retarder is now consistent with the documentation. If a model created in version 5.0 is opened in version 5.2a, the expression for the Retardance of any Circular Wave Retarder node is multiplied by 2.The Deposited Ray Power node for absorbing domains is obsolete and will be removed in future versions. For simulations in which rays generate heat due to absorption, the Ray Heat Source multiphysics node should be used instead.