Crash at com.apple.backboardd, what's the reason?

it has happened on iOS 15.2.1 this is the content of ips:

"cpuType" : "ARM-64", "procName" : "backboardd", "procPath" : "/usr/libexec/backboardd", "parentProc" : "launchd", "parentPid" : 1, "coalitionName" : "com.apple.backboardd", "crashReporterKey" : "ef17e4078ac993f140daf6f9b68615b883b55685", "basebandVersion" : "2.23.02", "isCorpse" : 1, "exception" : {"codes":"0x0000000000021aaa, 0x0000000000000000","rawCodes":[0],"type":"EXC_RESOURCE","signal":"SIGKILL"}, "termination" : {"flags":2,"code":"namespace":"PORT_SPACE","indicator":"(Limitports) Exceeded system-wide per-process Port Limit"}, "faultingThread" : 2,

Crash at com.apple.backboardd, what's the reason?
 
 
Q