Title: Fatal Error:
Last modified: August 27, 2024

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# Fatal Error:

 *  Resolved [narkanister](https://wordpress.org/support/users/narkanister/)
 * (@narkanister)
 * [1 year, 7 months ago](https://wordpress.org/support/topic/fatal-error-4733/)
 * Fatal error: Uncaught TypeError: Return value of NinjaForms\Includes\Entities\
   NfSite::jsonSerialize() must be an instance of NinjaForms\Includes\Entities\mixed,
   array returned in /wp-content/plugins/ninja-forms/includes/Entities/NfSite.php:
   77
 * Errors started Mon, 26 Aug, 21:18
 * Ninja Forms version **3.8.13** – WordPress version: **6.6.1**
 * Front end is working. Cannot log into back end.
 * Disabled Ninja forms. Able to log in again. Reinstalled Ninja forms. Same issue–
   unable to access backend – fatal error.
 * Rolled back to Ninja Forms **3.8.12** and all working ok again.
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Ffatal-error-4733%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 6 replies - 1 through 6 (of 6 total)

 *  [Faisal Ahammad](https://wordpress.org/support/users/faisalahammad/)
 * (@faisalahammad)
 * [1 year, 7 months ago](https://wordpress.org/support/topic/fatal-error-4733/#post-17977617)
 * Hi there,
 * Sorry for the trouble. To further investigate your issue, we will need an export
   copy of your form and system report. Sharing this here will make it public, which
   could pose a security issue for your website.
 * Please reach out to our [Customer Success](https://ninjaforms.com/account/support/)
   team for further assistance. They can delve deeper into the problem and help 
   ensure that you can download your form submissions smoothly.
 * Regards
   Faisal
 *  [nickwilmot](https://wordpress.org/support/users/nickwilmot/)
 * (@nickwilmot)
 * [1 year, 7 months ago](https://wordpress.org/support/topic/fatal-error-4733/#post-17978588)
 * Same issue here. PHP 7.4 running on this server – if that’s releated? As it’s
   a live site and NF is non-critical, I’ve just had to disable NF via Recover Mode
   for the time being. Cannot export the System Report as the plugin will not run.
    -  This reply was modified 1 year, 7 months ago by [nickwilmot](https://wordpress.org/support/users/nickwilmot/).
 *  [nickwilmot](https://wordpress.org/support/users/nickwilmot/)
 * (@nickwilmot)
 * [1 year, 7 months ago](https://wordpress.org/support/topic/fatal-error-4733/#post-17978595)
 * [@narkanister](https://wordpress.org/support/users/narkanister/) Just realised
   who the OP is 👋!!
 *  [databird](https://wordpress.org/support/users/sberney/)
 * (@sberney)
 * [1 year, 7 months ago](https://wordpress.org/support/topic/fatal-error-4733/#post-17978615)
 * Same here :
    - PHP 7.4.33
    - WP 6.5.5
    - NF 3.8.13
    - Try to install “ninja-forms-multi-part-v3.0.26”
 *  [Faisal Ahammad](https://wordpress.org/support/users/faisalahammad/)
 * (@faisalahammad)
 * [1 year, 7 months ago](https://wordpress.org/support/topic/fatal-error-4733/#post-17978708)
 * Hi [@narkanister](https://wordpress.org/support/users/narkanister/), [@nickwilmot](https://wordpress.org/support/users/nickwilmot/)
   and [@sberney](https://wordpress.org/support/users/sberney/),
 * We apologize for the inconvenience. We are currently addressing the fatal error
   that arises when using PHP version **v7.4** with Ninja Forms **v3.8.13**, and
   we are planning to resolve this issue in our upcoming release which we are testing
   now.  
 * In the meantime, we recommend upgrading your PHP version to **v8.x.x** or alternatively,
   you can download Ninja Forms version **v3.8.12** from [https://downloads.wordpress.org/plugin/ninja-forms.3.8.12.zip](https://downloads.wordpress.org/plugin/ninja-forms.3.8.12.zip)
   and install it manually via the **Plugins > Add New** page using WordPress’ Upload
   Plugin functionality.  
 * Once you have installed and activated version **3.8.12**, the issue should go
   away.    
 * Please give it a try, and let us know how it goes.
 * Thanks
   Faisal 
 *  Thread Starter [narkanister](https://wordpress.org/support/users/narkanister/)
 * (@narkanister)
 * [1 year, 7 months ago](https://wordpress.org/support/topic/fatal-error-4733/#post-17978836)
 * Thanks for the prompt response [@faisalahammad](https://wordpress.org/support/users/faisalahammad/).
   Yes this server is still php 7.4
 * Cheers. 
   (And hi to the man [@nickwilmot](https://wordpress.org/support/users/nickwilmot/)
   👊🏻)

Viewing 6 replies - 1 through 6 (of 6 total)

The topic ‘Fatal Error:’ is closed to new replies.

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## Tags

 * [fatal error](https://wordpress.org/support/topic-tag/fatal-error/)

 * 6 replies
 * 4 participants
 * Last reply from: [narkanister](https://wordpress.org/support/users/narkanister/)
 * Last activity: [1 year, 7 months ago](https://wordpress.org/support/topic/fatal-error-4733/#post-17978836)
 * Status: resolved