I'm going to start with answering a couple of questions from a post in the Mesh Forum.
1) If the normal map is set to "Brightness", the shiny and environment spinners no longer have any effect. Instead, both appear to be stuck on maximum setting.
If I create a cube and apply ‘Brightness’ legacy bump settings, then select the Specular tab, I can select any of the legacy Shininess values (None, Low, Med, High) and I don’t see any other controls until I apply a specular map texture. Once I’ve applied a specular texture, the controls function normally, defaulting to Glossiness of 51 and Environment Intensity of 0. Pushing the up and down arrows on each changes values, but if this does not work for you, you may be seeing a bug. 2) You can no longer set the repeats of the normal map independently. Instead they are fixed to those set for the diffuse map. Changing them while vieweing the normal map (selected in the dropdown) has no effect.
First you must select a normal map texture (instead of one of the legacy bumpmap settings), by clicking on the “X” image in the normal map texture pane. After you have selected a normal map, you can adjust the offset and repeats of the normal and specular channels independently from the diffuse channel settings. The current release viewer has the bumpmap texturing slaved to the diffuse map settings and that behavior cannot be changed without breaking existing content.
If either of these problems are still happening for you after reviewing this feedback, please file a MATBUG JIRA with detailed steps.