"Unsupported event" error coming from container JS

Hi! On some of the websites I’m working with Piwik PRO on, sometimes I’m noticing this kind of error, seemingly coming from container JS file:

I’m pretty sure this is effect of some weird dataLayer events posted by other solutions that are implemented on the website (other consent managers for example).

Is there any way I could debug what is exactly causing it? I’d like to make sure this doesn’t disrupt the tracking, as well maybe try to get rid of this error.

Or maybe there are some specific known situations when I would get “Unsupported event” error? I haven’t encountered such an error before, so I kind of don’t know how to approach it. I checked the dataLayer contents and only bad thing I notice are some events without “event” node. Maybe that is it?

I will be thankful for any tips, cheers!

Hi @gonerator,

This error will occur when there’s something in dataLayer that our container can’t handle.
Types of values for which this error will occur: null, undefined, string, or number

So one of the tools you are using must be pushing an unsupported value to the dataLayer.

Best way to debug it would be to first find what is the value pushed and then figure out where from it comes.

If I were to guess there might be a logic that sends either an object or null value to the dataLayer, but again that’s just a blind guess.


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@Oliwer_Kaczmarek thank you, now that you said that, that makes perfect sense! That’s exactly the tip I needed :slight_smile: As you said, there must be something in the page that sends some event that doesn’t make sense as an event - a string or something. I will look for it, cheers!