added null check for queueName

@@ -21,6 +21,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import io.netty.channel.EventLoopGroup;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.util.StringUtils;
 import org.thingsboard.common.util.ListeningExecutor;
 import org.thingsboard.rule.engine.api.MailService;
 import org.thingsboard.rule.engine.api.RuleEngineRpcService;
@@ -43,6 +44,7 @@ import org.thingsboard.server.common.data.rule.RuleNode;
 import org.thingsboard.server.common.msg.TbActorMsg;
 import org.thingsboard.server.common.msg.TbMsg;
 import org.thingsboard.server.common.msg.TbMsgMetaData;
+import org.thingsboard.server.common.msg.queue.ServiceQueue;
 import org.thingsboard.server.common.msg.queue.ServiceType;
 import org.thingsboard.server.common.msg.queue.TopicPartitionInfo;
 import org.thingsboard.server.dao.alarm.AlarmService;
@@ -178,6 +180,9 @@ class DefaultTbContext implements TbContext {
     }
 
     private TopicPartitionInfo resolvePartition(TbMsg tbMsg, String queueName) {
+        if (StringUtils.isEmpty(queueName)) {
+            queueName = ServiceQueue.MAIN;
+        }
         return mainCtx.resolve(ServiceType.TB_RULE_ENGINE, queueName, getTenantId(), tbMsg.getOriginator());
     }