# Mautic Form Preview / Form Submission - 500 Error

**URL:** <https://forum.mautic.org/t/mautic-form-preview-form-submission-500-error/20623>\
**Category:** Product Support\
**Tags:** mautic-3\
**Created:** [August 28, 2021, 4:14am UTC](https://forum.mautic.org/t/mautic-form-preview-form-submission-500-error/20623 "2021-08-28T04:14:09Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![segrand](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/segrand/32/3267_2.png) [@segrand](https://forum.mautic.org/u/segrand)\
**Post date:** [August 28, 2021, 4:14am UTC](https://forum.mautic.org/t/mautic-form-preview-form-submission-500-error/20623/1 "2021-08-28T04:14:09Z")

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**Your software**  
My Mautic version is: 3  
My PHP version is: 7.4  
My Database type and version is: Mariadb

**Your problem**  
My problem is:  
While submitting the form, it gives 500 error. Same error when I try to preview the form.

# Uh oh! I think I broke it. If I do it again, please report me to the system administrator!

#### **500** Internal Server Error

These errors are showing in the log:  
[2021-08-28 09:43:05] mautic.CRITICAL: Uncaught PHP Exception RuntimeException: “Unable to write in the cache directory (/opt/bitnami/mautic/app/../var/tmp/twig/1a).” at /opt/bitnami/mautic/vendor/twig/twig/src/Cache/FilesystemCache.php line 61 {“exception”:“[object] (RuntimeException(code: 0): Unable to write in the cache directory (/opt/bitnami/mautic/app/../var/tmp/twig/1a). at /opt/bitnami/mautic/vendor/twig/twig/src/Cache/FilesystemCache.php:61)”}

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<div class="post-metadata">

**Author:** ![adiux](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/adiux/32/5793_2.png) [@adiux](https://forum.mautic.org/u/adiux)\
**Post date:** [August 30, 2021, 8:50am UTC](https://forum.mautic.org/t/mautic-form-preview-form-submission-500-error/20623/2 "2021-08-30T08:50:10Z")

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This looks like it is a permission problem. Or maybe the folder does not exist?

You can check the status in Settings \> System Info

Here are some more information about permissions and how to solve it:

> **[File ownership and permissions](https://docs.mautic.org/en/troubleshooting/file-ownership-and-permissions#how-to-fix-permission-related-problems-in-mautic)**
>
> . If you experience errors like the following:. mautic.WARNING: PHP Warning require(/mautic/var/cache/prod/doctrine/orm/Proxies/CGMauticCategoryBundleEntityCategory.php): failed to open stream: No such file or directory - in file...

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<div class="post-metadata">

**Author:** ![condoexchange](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/condoexchange/32/682_2.png) [@condoexchange](https://forum.mautic.org/u/condoexchange)\
**Post date:** [October 4, 2021, 2:09pm UTC](https://forum.mautic.org/t/mautic-form-preview-form-submission-500-error/20623/3 "2021-10-04T14:09:55Z")

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Unable to edit Forms. " Uh oh! I think I broke it. If I do it again, please report me to the system administrator! #### **500** Internal Server Error"

Please advice how to resolve.

Upon checking the log, this errors shows up:  
[2021-10-04 09:02:46] mautic.CRITICAL: Uncaught PHP Exception Symfony\Component\Form\Exception\UnexpectedTypeException: “Expected argument of type “null or string”, “boolean” given” at /home/abc/public\_html/www/mautic/vendor/symfony/form/Extension/Core/DataMapper/RadioListMapper.php line 49 {“exception”:"[object] (Symfony\Component\Form\Exception\UnexpectedTypeException(code: 0): Expected argument of type “null or string”, “boolean” given at /home/abc/public\_html/www/mautic/vendor/symfony/form/Extension/Core/DataMapper/RadioListMapper.php:49)"}