Harvester sync logs error

Hi guys,

I got many times this type of error in my logs.
2021-06-02T10:12:40.130 full_node full_node_server : WARNING Invalid handshake with peer. Maybe the peer is running old software.

and this
2021-06-02T10:21:13.168 harvester chia.plotting.plot_tools: WARNING Have multiple copies of the plot H:\plots\plot-k32-2021-05-27-08-05

I use a first computer on windows 10 and chia 1.1.6 with the gui and a second computer (slave) windows 10 chia 1.1.6 (harvester mode).

Could you help me to understand this warnings ?