When i click on the Vertex Paint Tab it crashes or when i click on a Static mesh it also. So i made and new Project to see if it happen again on a clean new project and it is doing it also.i think it has to do something with Substance Plugin cause when i apply the Substance Plugin Material and go to Vertex Paint it crashes. Here the Project log on crashlink text
It is a Bug on UE4 side tho to the major changes done in 4.16 theirs a forum in Allegorithmic site UE4 crash when pressing paint (vertex paint)