# Unsuscribe links sending to 500 Internal Server Error after update

**URL:** <https://forum.mautic.org/t/unsuscribe-links-sending-to-500-internal-server-error-after-update/34136>\
**Category:** Product Support\
**Created:** [November 15, 2024, 6:45pm UTC](https://forum.mautic.org/t/unsuscribe-links-sending-to-500-internal-server-error-after-update/34136 "2024-11-15T18:45:17Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![zero477](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/zero477/32/10873_2.png) [@zero477](https://forum.mautic.org/u/zero477)\
**Post date:** [November 15, 2024, 6:45pm UTC](https://forum.mautic.org/t/unsuscribe-links-sending-to-500-internal-server-error-after-update/34136/1 "2024-11-15T18:45:17Z")

</div>

**Your software**  
My Mautic version is: v5.1.1  
My PHP version is: PHP Version 8.1.30  
My Database type and version is: 10.5.27-MariaDB-deb11-log

**Your problem**  
My problem is: Unsuscribe links sending to **500** Internal Server Error

These errors are showing in the log:  
[2024-11-15T00:31:30.565426+00:00] app.ERROR: Invalid clickthrough value: 3DYTo1Ont= {“exception”:“[object] (Mautic\CoreBundle\Exception\InvalidDecodedStringException(code: 0): The string �6\u0013�S� is not a serialized array at //zutypyvjgb/public\_html/app/bundles/CoreBundle/Helper/ClickthroughHelper.php:34)”} {“hostname”:“\*\*\*\*”,“pid”:4080843}

[2024-11-15T00:31:31.259200+00:00] app.ERROR: Invalid clickthrough value: 3DYTo1OntzOjY6InNvdXJjZ= {“exception”:“[object] (Mautic\CoreBundle\Exception\InvalidDecodedStringException(code: 0): The string �6\u0013�S��3�c�’6�W&6 is not a serialized array at /public\_html/app/bundles/CoreBundle/Helper/ClickthroughHelper.php:34)”} {“hostname”:“######”,“pid”:4080843}

[2024-11-15T01:21:31.970670+00:00] app.ERROR: Invalid clickthrough value: 3DYTo1OntzOjY6InNvd= {“exception”:“[object] (Mautic\CoreBundle\Exception\InvalidDecodedStringException(code: 0): The string �6\u0013�S��3�c�’6� is not a serialized array at /public\_html/app/bundles/CoreBundle/Helper/ClickthroughHelper.php:34)”} {“hostname”:“######”,“pid”:4090749}

Steps I have tried to fix the problem:

I have been playing with the preferences of email settings and clearing cache. Following this video: [https://www.youtube.com/watch?v=JdgVdiv1JhU](https://www.youtube.com/watch?v=JdgVdiv1JhU)

I think it is an error related to Mautic Update because it did not happen before. I realize because a contact notified us that he could not unsuscribe.