SVC_PINGS messages are sent only when You (or other human-player) presses a TAB (IN_SCORE) button. If that one is pressed You cannot chose from the main podbotmenu "Kill all bots" item. How You have done it?
Can You test it so - switch off that Mercylezz's plugin, put pb_latencybot to 0 (to make sure this function is not working there), then try kill all bots with those problematic plugins. If the crash still happens, it has nothing with ping messages. Then please test again with any previous (V3B20h i.e) version (juts put the binary on the server) to confirm again it doesn't crash with that version, but it does with 2 newest ones.