I have just upgraded from version 5 to 6. Now the problem is that many types of events resolve to “(((...args: any[]) => void) | undefined”. In version <6, these were named events, which are also listed accordingly in the documentation.
As a result, the projects can no longer be build. This also happens if version 6 is installed directly in an empty project.
Examples:
Are we doing something wrong here or are the type definitions incorrect?
Hi, Sam.
I've tried to reproduce the reported issue in the project attached to my reply but with no success.
Can you please check the attached example and let me know if the issue is replicable on your end? If the project is working correctly, can you please try to edit it in a way the issue from the screenshots can be replicated?
When you are able to replicate the issue, please send us the edited project back for furhter investigation.
Last but not least, is there a chance that you are using Vue 2 in your project? I am asking this because with version 6.0.0 of the Kendo UI for Vue Native components, Vue 2 is no longer supported by the suite. More info about the Vue 2 end of support can be found on this link.
I just created a new Vue project and installed some Kendo components:

Version 5.2.0

I have also encountered this problem with a new standard vue 3.5.13 vite project (typescript v~5.6.3).
It appears to happen on all kendo control events. For example, the RadioGroup (v6.0.1) change event:
<RadioGroup :id="props.id" :value="props.value" :checked="props.value" @change="handleOnChange" />
Shows the error:
index.d.mts(2938, 1): The expected type comes from property 'onChange' which is declared here on type ...
The kendo type definition file defines onChange as:
This stackblitz project illustrates the issue - error occurs when attempting to build.
Hey, Sven,
Yes, this is the official item - thank you for sharing it. I have also increased its priority with this request.
Is there something new and when will it be fixed?
Due to this bug the current version is not usable.
Hi, Sven,
We are doing everything to address this issue as soon as possible. I have increased the item severity.
Apologies for any inconvenience this might have caused you. Please let me know if I can assist you further.
I am just now setting up some new Vue screens with kendo for Vue and Type script. I spent quite some time trying to figure out if I was causing this error for event handling and I am glad to see this issue here.
I see this was opened in Dec 2024 and is still an issue as of May 2025. Does that mean not many people are using Kendo Vue + TypeScript? or they found work arounds? or people just stay on Version 5? This is making me a little nervous about jumping in considering a basic File > New project is not usable?
Hi, Timothy,
We totally understand your concerns, and we're really sorry for the trouble this bug has caused. It hadn't been prioritized earlier because other issues with higher priority—prioritized based on severity and recency. But thanks to the latest reports, this bug is now at the top of our backlog and scheduled for the upcoming sprint. We'll make sure to update its status once it's fixed.Again, we're sorry for any uncertainty you felt about upgrading the product. If there's anything else I can help with, just let us know - we will be happy to assist.