If you try to change the color or material of a selected model using SelectRibbonTool, Roblox Studio crashes.
Fast repro in the command bar:
-- color crash (select a color when prompted)
local model = Instance.new("Model",workspace)
game.Selection:Set{model}
PluginManager():CreatePlugin():SelectRibbonTool(Enum.RibbonTool.ColorPicker,UDim2.new())
-- material crash (select a material when prompted)
local model = Instance.new("Model",workspace)
game.Selection:Set{model}
PluginManager():CreatePlugin():SelectRibbonTool(Enum.RibbonTool.MaterialPicker,UDim2.new())