Topic "__change_events" failed read schema

[gaozhangmin]

2022-02-16 11:20:15.155 [ForkJoinPool.commonPool-worker-11] WARN  org.apache.pulsar.broker.service.schema.AvroSchemaBasedCompatibilityCheck - Error during schema compatibility check: Unable to read schema:
{
  "type" : "record",
  "name" : "PulsarEvent",
  "namespace" : "org.apache.pulsar.common.events",
  "fields" : [ {
    "name" : "actionType",
    "type" : [ "null", {
      "type" : "enum",
      "name" : "ActionType",
      "symbols" : [ "INSERT", "DELETE", "UPDATE", "NONE" ]
    } ],
    "default" : null
  }, {
    "name" : "eventType",
    "type" : [ "null", {
      "type" : "enum",
      "name" : "EventType",
      "symbols" : [ "TOPIC_POLICY", "TRANSACTION_BUFFER_SNAPSHOT" ]
    } ],
    "default" : null
  }, {
    "name" : "topicPoliciesEvent",
    "type" : [ "null", {

[codelipenghui]

@gaozhangmin This is a breaking change introduced in 2.8.0, and #12598 has fixed the issue.