What to do in case of an ELEM UNDEF error

Hey there :wave:

You may have noticed an ELEM UNDEF error message appearing in some of your apps recently. This happens when we have a synchronisation issue, your data is still there but unreadable by the editor.

It’s something the tech team is working hard to fix. However, the fix may still be a few weeks away because the upcoming release of components is slowing down our investigations.

In the meantime, here’s a guide of what to do when it happens:

  1. do NOT delete the element or its container because that will make it impossible to recover

  2. use the restoration popup to provide us with some context about when the issue happened and try restoring the element:

image (1)

This will automatically create a notification on our side that we will investigate. Still we encourage you to also open a support ticket with us so you can see the progress we make

  1. open a support ticket with ELEM UNDEF in your ticket title, we will prioritize it and recover the element for you (as long as you have followed step 1 and made sure NOT to delete it or a parent container.

Other things you can try

  1. if you have custom code in workflows or formulas, you can try opening the editor in safe mode to see if the issue is still there. if it’s not, you can either hunt down the custom code that could be creating the conflict or open a support ticket so we can help you find the source of the error. Make sure to include ELEM UNDEF in your ticket title so we can prioritize it

  2. if you have access to editor backups and find a version that you are happy to work with (no work lost and no elem undef), you can rollback to that version

We know this is not ideal but rest assured we ARE working on the topic and will do our best to support you while it is being resolved.


Updated: December 1st, 2023


Another strategy :


But then you lose the ELEM UNDEF, you don’t recover it. So I wouldn’t recommend that option unless you’re ok redesigning what you had there

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yes yes of course, but in case of there is many other things that are not in this UNDEF, this avoid to redesign the whole div
In my example, the image, i didn’t needed to remake it

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@Joyce Any update on this bug? It’s now more than 10 days and I am still getting the error.

Hi @mahrukh_nocode :wave:

The tech team is exploring two main theories but have to wait for the big release of libraries and components before they can test these two potential explanations further.

We can’t commit on a bug fix date because:

  • we can’t know for sure we have identified the root cause of the issue yet
  • we won’t be able to investigate further until we release libraries and components

Have you created bug ticket here? If not, please do so that we can assist you further.

Thanks for the tip @Zacharyb! My component was displayed fine (after recovered from ELEM UNDEF). But I couldn’t select that element anymore, so I deleted it :slight_smile:

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Hello don’t know if it’s helps, but Webflow seemed to have the same kind of error maybe, maybe worth to investigate on how they did find this “weird” bug (their words)

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WeWeb is getting a bit buggy. I’m working on my app and have already encountered 3 ELEMENT UNDF errors. I was able to recover one of them using the Recover Tool, but it didn’t work for the other two elements. I’m starting to get worried about continuing to work on my app in case I lose more elements. I’ve also already created support tickets that have not been addressed yet. I also don’t have two editors open simultaneously to reduce the problem. I hope WeWeb can quickly get this under control or provide a workaround to prevent these errors at least.

I have found a workaround that at least speeds up the recovery process a bit.

  1. The element is displayed as “ELEMNT UNDF” - Then you can try using the Recover Tool to retrieve the element.
  2. If step 1 doesn’t work, you add a DIV to the section (otherwise, WeWeb says “You can’t paste something here…”).
  3. Then you go to the your Backup and copy the functioning DIV, then return to the Main Editor and paste the “functioning” element onto the newly added DIV.
  4. The editor will recognize the element then and can read it again. There will be two identical DIVs in the section, but you can delete one of them.
  5. This has worked really well for me now…

*after going through this entire process, when there are two DIVs present, it appears as if you have two identical elements. However, it’s important to closely examine the structure of these DIVs. One of the DIVs is fully visible in the preview, but in the layout (on the left), it’s empty. When workflows reference this DIV, make sure to verify that you are deleting the correct DIV and then fill it back in with the missing elements.


Hi @tillyboard :wave:

Yeah, I definitely understand your concerns. It’s top of our list to solve this issue. The tech team has already identified (and fixed) a few situations where ELEM UNDEF errors appeared but there’s still work to be done because we haven’t yet been able to identify / reproduce every situation where it can happen.

That’s why we ask you to create a support ticket with as much information as possible whenever it happens to you. We’re not always able to reply right away but it helps us a lot to identify potential causes, reproduce that specific ELEM UNDEF, and fix it.

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Thanks so much for taking the time to share this, Fynn! REALLY appreciate it :pray:

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@Joyce This bug is causing issues.

I cannot recover the element because it is not clickable. I had to rebuild the part from scratch as it was the side menu, and the app couldn’t work without a side menu. Unfortunately, just two days after rebuilding it, we will now need to build it again.

I have submitted a bug report with videos and screenshots, but I’m unsure if another report will help.

Is there any expected timeline on when this will be resolved?

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Hello !
I suggest to try this What to do in case of an ELEM UNDEF error - #3 by Zacharyb

with this you don’t have to rebuild everything

Hi @Joyce - is there an update on this issue? Thanks.

Hi @ben, @Himanshu :wave:

This matter has been partially resolved but there’s no expected timeline on when this will be resolved entirely.

The reason for this is that undefined elements can be caused by different things and are very hard to reproduce without specific information about a project. We have fixed all identified causes.

With that in mind, @Himanshu, don’t hesitate to create several reports! We’ll look at each one separately and it will help us identify and fix other potential causes.

We recommend you create a new bug ticket every time you see this happen with as much information as possible about when/how it happened. The more undefined elements we can reproduce, the quicker we can resolve this matter completely.

Hey @Joyce thanks for responding.

The occurrences have reduced drastically for us. In the last three weeks, it probably happened only once.

We’ve since converted everything inside of the sidebar (the element in question) to a component, and when it occurred, we didn’t lose our work, and the component could be used.

@Zacharyb thanks for the tip. Will try it next time it occurs (hopefully not soon)


Ah that’s great to read! Thanks for lettings us know :slight_smile: Glad you didn’t lose any work!!

One thing, careful if your only item in a section that has this bug, has only 1 component (and within subcomponent), in this case it doesn’t work !

@Joyce I just hit one of these for the first time. Restore did not work. Support ticket submitted. Help! :pray:

CC @caffeinatedwes

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