Can't draw lines on a dedicated server?

I’m trying to draw on a plane in multiplayer and I’m using a dedicated server. I’m sending the points to be drawn to the server and to the clients as well (multicast). It seems to work on the clients (they can see the points used to draw the lines) but I’m getting this on the server log:

  40]Blueprint:Warning: Warning EndDrawCanvasToRenderTarget: Context must be valid. 
  40]LogScript:Warning: Accessed None trying to read property CallFunc_BeginDrawCanvasToRenderTarget_Canvas BP_WhiteBoard_C 

It seems the offender blueprint node is Begin Draw Canvas to Render Target. Can’t a dedicated server use this node to get a valid canvas and drawing context?