Bug explanation
The version of the MaterialDesignThemes.Wpf.dll assembly included in the 4.7.0 package is 1.0.1, which is incorrect. The version included in the previous 4.6.1 package was correctly set at 4.6.1. This causes an incompatibility when trying to use this latest package in conjunction with MaterialDesignExtensions, which has a dependency of version 3.2 or greater.
Version
4.7.0