I got these messages scrolling on the console screen when I connect n-tron L2 switch to any switchport

dh#

<187> Mar 24 23:25:05 dh-1 DOT1S[dtlTask]: dot1s_txrx.c(306) 273 %% dot1sBpduReceive(): Discarding the BPDU, since it is an invalid BPDU type

What can be done to stop them?

Thank you for help.