local agent dev -> "RPC error: Error: Method toJSON does not exist"

agents_react.js?v=96d2183a:799 Uncaught (in promise) Error: Method toJSON does not exist
    at Object.onMessage (agents_react.js?v=96d2183a:799:28)
    at PartySocket.onMessage (agents_react.js?v=96d2183a:652:104)
    at PartySocket.sentryWrapped (@sentry_remix.js?v=96d2183a:10441:17)
    at WebSocket.<anonymous> (agents_react.js?v=96d2183a:148:12)
    at WebSocket.sentryWrapped (@sentry_remix.js?v=96d2183a:10441:17)

RPC error: Error: Method toJSON does not exist
      at null.<anonymous>
  (file:///Users/pk2/Avnir/cfw-avnir-agent/node_modules/agents/src/index.ts:445:23)
      at Agent.onMessage
  (file:///Users/pk2/Avnir/cfw-avnir-agent/node_modules/agents/src/index.ts:418:27)
      at _AgentSupervisor.webSocketMessage
  (file:///Users/pk2/Avnir/cfw-avnir-agent/node_modules/partyserver/src/index.ts:386:17)