Cannot subscribe to the event when a user joins or leaves a channel

[aayani]

instead getting an error with this JSON in response {"type":"error","error":{"msg":"invalid message type: null","code":3,"source":"gs-bom-hhur"}}

[7c]

I also keep getting this strange bot message to onMessage. Any clue why this might be ?

2019-08-20T15:21:24.460Z bot onMessage was called
2019-08-20T15:21:24.460Z bot msg:{"type":"error","error":{"msg":"invalid message type: null","code":3,"source":"gs-iad-4jhr"}}
2019-08-20T15:21:49.608Z bot onMessage was called
2019-08-20T15:21:49.608Z bot msg:{"type":"error","error":{"msg":"invalid message type: null","code":3,"source":"gs-iad-4jhr"}}
2019-08-20T15:22:14.460Z bot onMessage was called
2019-08-20T15:22:14.460Z bot msg:{"type":"error","error":{"msg":"invalid message type: null","code":3,"source":"gs-iad-4jhr"}}
2019-08-20T15:22:39.465Z bot onMessage was called
2019-08-20T15:22:39.465Z bot msg:{"type":"error","error":{"msg":"invalid message type: null","code":3,"source":"gs-iad-4jhr"}}
2019-08-20T15:23:04.461Z bot onMessage was called
2019-08-20T15:23:04.461Z bot msg:{"type":"error","error":{"msg":"invalid message type: null","code":3,"source":"gs-iad-4jhr"}}
2019-08-20T15:23:29.462Z bot onMessage was called
2019-08-20T15:23:29.462Z bot msg:{"type":"error","error":{"msg":"invalid message type: null","code":3,"source":"gs-iad-4jhr"}}

[guigallo]

receiving same error many times too:

{ type: 'error', error: { msg: 'invalid message type: null', code: 3, source: 'gs-gru-3ydt' } }

[elDudarino]

Was anyone able to figure this out? I've been trying to subscribe to _join events and none appear to work. I am trying to capture when a user joins the general channel or others but never seems to trigger:

if (data.subtype !== 'bot_message') {
	if (data.type === 'message') {
		
		if (data.subtype == 'member_joined_channel') {
			console.log('member join subtype');
			console.log(data);
			const params = {
				icon_emoji: ':information_source:',
			};
			
			bot.postMessage(notifications_channel_id, 'NEW CHANNEL JOIN: member_joined_channel subtype triggered' , params);
		}

		if (data.subtype == 'team_join') {
			console.log('member join team_join subtype');
			console.log(data);
			const params = {
				icon_emoji: ':information_source:',
			};
			
			bot.postMessage(notifications_channel_id, 'NEW CHANNEL JOIN: team_join subtype triggered' , params);
		}

		if (data.subtype == 'channel_join') {
			console.log('channel_join  join subtype');
			console.log(data);
			const params = {
				icon_emoji: ':information_source:',
			};
			
			bot.postMessage(notifications_channel_id, 'NEW CHANNEL JOIN: channel_join subtype triggered' , params);
		}

.....................

Thank you!