Maybe a real (not too big) issue here; after starting the editor with the Plugin turned on my main project, the Output log shows these warnings:
LogStreaming: Warning: Failed to read file '../../../Engine/Plugins/Marketplace/LogicDriver/Content/Brushes/Button.png' error.
LogSlate: Could not find file for Slate resource: ../../../Engine/Plugins/Marketplace/LogicDriver/Content/Brushes/Button.png
LogStreaming: Warning: Failed to read file '../../../Engine/Plugins/Marketplace/LogicDriver/Content/Brushes/Button_Hovered.png' error.
LogSlate: Could not find file for Slate resource: ../../../Engine/Plugins/Marketplace/LogicDriver/Content/Brushes/Button_Hovered.png
LogStreaming: Warning: Failed to read file '../../../Engine/Plugins/Marketplace/LogicDriver/Content/Brushes/Button_Pressed.png' error.
LogSlate: Could not find file for Slate resource: ../../../Engine/Plugins/Marketplace/LogicDriver/Content/Brushes/Button_Pressed.png
LogStreaming: Warning: Failed to read file '../../../Engine/Plugins/Marketplace/LogicDriver/Content/Brushes/Button_Disabled.png' error.
LogSlate: Could not find file for Slate resource: ../../../Engine/Plugins/Marketplace/LogicDriver/Content/Brushes/Button_Disabled.png
What do you think? : ]