# ConvertKit (Kit) Subscribe Form Error After Updating Beaver Builder + PowerPack

**URL:** <https://community.wpbeaverbuilder.com/t/convertkit-kit-subscribe-form-error-after-updating-beaver-builder-powerpack/20069>\
**Category:** Beaver Builder\
**Tags:** beaver-builder\
**Created:** [March 5, 2026, 9:35pm UTC](https://community.wpbeaverbuilder.com/t/convertkit-kit-subscribe-form-error-after-updating-beaver-builder-powerpack/20069 "2026-03-05T21:35:49Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![BlueCastle3](https://community.wpbeaverbuilder.com/letter_avatar_proxy/v4/letter/b/a5b964/32.png) [@BlueCastle3](https://community.wpbeaverbuilder.com/u/BlueCastle3)\
**Post date:** [March 5, 2026, 9:35pm UTC](https://community.wpbeaverbuilder.com/t/convertkit-kit-subscribe-form-error-after-updating-beaver-builder-powerpack/20069/1 "2026-03-05T21:35:49Z")

</div>

After updating **Beaver Builder Plugin (Pro Version)** and **PowerPack for Beaver Builder** to the latest versions, the **PowerPack Subscribe Form module connected to my ConvertKit** account stopped working.

Now when the form is submitted, it triggers a fatal error:

Too few arguments to function FLBuilderServiceConvertKit::subscribe(), 3 passed and exactly 4 expected

Rolling the plugins back resolved the issue and the form works normally again.

**Working versions:**

Beaver Builder Plugin (Pro Version): 2.9.0.5  
PowerPack for Beaver Builder: 2.40.1.6

Has anyone else encountered this compatibility issue between **Beaver Builder Plugin (Pro Version)** and **PowerPack for Beaver Builder** when using ConvertKit?

I just happened to notice that my subscriber count dropped to zero which prompted me to test my opt-in forms.

I should also note that it’s worked fine over the past 5 years as I’ve been updating the plug-ins. This is the first time I’ve encountered this issue.

Thanks,

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<div class="post-metadata">

**Author:** ![pross](https://community.wpbeaverbuilder.com/user_avatar/community.wpbeaverbuilder.com/pross/32/883_2.png) [@pross](https://community.wpbeaverbuilder.com/u/pross)\
**Post date:** [March 10, 2026, 6:31pm UTC](https://community.wpbeaverbuilder.com/t/convertkit-kit-subscribe-form-error-after-updating-beaver-builder-powerpack/20069/2 "2026-03-10T18:31:36Z")

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Hi there.

Yes it is an issue in 2.10 release, fortunatly the fix is super simple while you wait for the fix to get into a release:

Open the file: `bb-plugin/classes/services/class-fl-builder-service-convertkit.php` and change line 204 to this  
`public function subscribe( $settings, $email, $name, $custom_fields = array() ) {`

We are declaring the 4th arg optional which will fix the fatal error.