# Unsubscribe page throws error 500 **URL:** \ **Category:** Product Support\ **Created:** [May 18, 2020, 1:17pm UTC](https://forum.mautic.org/t/unsubscribe-page-throws-error-500/14372 "2020-05-18T13:17:16Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![gregorybrad](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/gregorybrad/32/2415_2.png) [@gregorybrad](https://forum.mautic.org/u/gregorybrad)\ **Post date:** [May 18, 2020, 1:17pm UTC](https://forum.mautic.org/t/unsubscribe-page-throws-error-500/14372/1 "2020-05-18T13:17:16Z")
**Your software** My Mautic version is: 2.16.2 My PHP version is: PHP Version 7.2.30 **Your problem** My problem is: Unsubscribe page gives error 500 These errors are showing in the log: [2020-05-18 09:52:03] mautic.CRITICAL: Uncaught PHP Exception Twig\_Error\_Loader: “Unable to find template “:blank\_left:base.html.twig” (looked into: /home/mymautic/public\_html/mautic.mymautic.com/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /home/mymautic/public\_html/mautic.mymautic.com/vendor/symfony/twig-bridge/Resources/views/Form).” at /home/mymautic/public\_html/mautic.mymautic.com/themes/blank\_left/html/message.html.twig line 1 {“exception”:"[object] (Twig\_Error\_Loader(code: 0): Unable to find template “:blank\_left:base.html.twig” (looked into: /home/mymautic/public\_html/mautic.mymautic.com/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /home/mymautic/public\_html/mautic.mymautic.com/vendor/symfony/twig-bridge/Resources/views/Form). at /home/mymautic/public\_html/mautic.mymautic.com/themes/blank\_left/html/message.html.twig:1)"} [2020-05-18 09:57:26] mautic.CRITICAL: Uncaught PHP Exception InvalidArgumentException: “The string b:8:{f:9:“fbhedf”;b:5:{v:3;f:47:“dbzcbvta.fifag”;v:4;v:713;}f:8:“fzbvy”;v:482;f:7:“fgbg”;f:55:“8fd58ca9568b1626458417”;f:7:“yfbe”;v:446780;f:0:“dubaafy”;b:4:{f:8:“fzbvy”;v:482;}} is not a serialized array” at /home/mymautic/public\_html/mautic.mymautic.com/app/bundles/CoreBundle/Helper/ClickthroughHelper.php line 46 {“exception”:"[object] (InvalidArgumentException(code: 0): The string b:8:{f:9:“fbhedf”;b:5:{v:3;f:47:“dbzcbvta.fifag”;v:4;v:713;}f:8:“fzbvy”;v:482;f:7:“fgbg”;f:55:“8fd58ca9568b1626458417”;f:7:“yfbe”;v:446780;f:0:“dubaafy”;b:4:{f:8:“fzbvy”;v:482;}} is not a serialized array at /home/mymautic/public\_html/mautic.mymautic.com/app/bundles/CoreBundle/Helper/ClickthroughHelper.php:46)"} [2020-05-18 09:57:33] mautic.CRITICAL: Uncaught PHP Exception InvalidArgumentException: “The string b:8:{f:9:“fbhedf”;b:5:{v:3;f:47:“dbzcbvta.fifag”;v:4;v:713;}f:8:“fzbvy”;v:482;f:7:“fgbg”;f:55:“8fd58caf12b80479303543”;f:7:“yfbe”;v:446776;f:0:“dubaafy”;b:4:{f:8:“fzbvy”;v:482;}} is not a serialized array” at /home/mymautic/public\_html/mautic.mymautic.com/app/bundles/CoreBundle/Helper/ClickthroughHelper.php line 46 {“exception”:"[object] (InvalidArgumentException(code: 0): The string b:8:{f:9:“fbhedf”;b:5:{v:3;f:47:“dbzcbvta.fifag”;v:4;v:713;}f:8:“fzbvy”;v:482;f:7:“fgbg”;f:55:“8fd58caf12b80479303543”;f:7:“yfbe”;v:446776;f:0:“dubaafy”;b:4:{f:8:“fzbvy”;v:482;}} is not a serialized array at /home/mymautic/public\_html/mautic.mymautic.com/app/bundles/CoreBundle/Helper/ClickthroughHelper.php:46)"} [2020-05-18 09:59:57] mautic.CRITICAL: Uncaught PHP Exception Twig\_Error\_Loader: “Unable to find template “:blank\_left:base.html.twig” (looked into: /home/mymautic/public\_html/mautic.mymautic.com/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /home/mymautic/public\_html/mautic.mymautic.com/vendor/symfony/twig-bridge/Resources/views/Form).” at /home/mymautic/public\_html/mautic.mymautic.com/themes/blank\_left/html/message.html.twig line 1 {“exception”:"[object] (Twig\_Error\_Loader(code: 0): Unable to find template “:blank\_left:base.html.twig” (looked into: /home/mymautic/public\_html/mautic.mymautic.com/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /home/mymautic/public\_html/mautic.mymautic.com/vendor/symfony/twig-bridge/Resources/views/Form). at /home/mymautic/public\_html/mautic.mymautic.com/themes/blank\_left/html/message.html.twig:1)"} [2020-05-18 10:18:20] mautic.CRITICAL: Uncaught PHP Exception InvalidArgumentException: “The string b:8:{f:9:“fbhedf”;b:5:{v:3;f:47:“dbzcbvta.fifag”;v:4;v:713;}f:8:“fzbvy”;v:482;f:7:“fgbg”;f:55:“8fd593e201929524407016”;f:7:“yfbe”;v:447486;f:0:“dubaafy”;b:4:{f:8:“fzbvy”;v:482;}} is not a serialized array” at /home/mymautic/public\_html/mautic.mymautic.com/app/bundles/CoreBundle/Helper/ClickthroughHelper.php line 46 {“exception”:"[object] (InvalidArgumentException(code: 0): The string b:8:{f:9:“fbhedf”;b:5:{v:3;f:47:“dbzcbvta.fifag”;v:4;v:713;}f:8:“fzbvy”;v:482;f:7:“fgbg”;f:55:“8fd593e201929524407016”;f:7:“yfbe”;v:447486;f:0:“dubaafy”;b:4:{f:8:“fzbvy”;v:482;}} is not a serialized array at /home/mymautic/public\_html/mautic.mymautic.com/app/bundles/CoreBundle/Helper/ClickthroughHelper.php:46)"} [2020-05-18 10:23:27] mautic.CRITICAL: Uncaught PHP Exception Twig\_Error\_Loader: “Unable to find template “:blank\_left:base.html.twig” (looked into: /home/mymautic/public\_html/mautic.mymautic.com/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /home/mymautic/public\_html/mautic.mymautic.com/vendor/symfony/twig-bridge/Resources/views/Form).” at /home/mymautic/public\_html/mautic.mymautic.com/themes/blank\_left/html/message.html.twig line 1 {“exception”:"[object] (Twig\_Error\_Loader(code: 0): Unable to find template “:blank\_left:base.html.twig” (looked into: /home/mymautic/public\_html/mautic.mymautic.com/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /home/mymautic/public\_html/mautic.mymautic.com/vendor/symfony/twig-bridge/Resources/views/Form). at /home/mymautic/public\_html/mautic.mymautic.com/themes/blank\_left/html/message.html.twig:1)"} [2020-05-18 10:29:41] mautic.CRITICAL: Uncaught PHP Exception Twig\_Error\_Loader: “Unable to find template “:blank\_left:base.html.twig” (looked into: /home/mymautic/public\_html/mautic.mymautic.com/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /home/mymautic/public\_html/mautic.mymautic.com/vendor/symfony/twig-bridge/Resources/views/Form).” at /home/mymautic/public\_html/mautic.mymautic.com/themes/blank\_left/html/message.html.twig line 1 {“exception”:"[object] (Twig\_Error\_Loader(code: 0): Unable to find template “:blank\_left:base.html.twig” (looked into: /home/mymautic/public\_html/mautic.mymautic.com/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /home/mymautic/public\_html/mautic.mymautic.com/vendor/symfony/twig-bridge/Resources/views/Form). at /home/mymautic/public\_html/mautic.mymautic.com/themes/blank\_left/html/message.html.twig:1)"} Steps I have tried to fix the problem: I have a feeling it has something to do with the PHP Version I am using or one of the components installed with PHP. That a built in function for string contamination is missing (or something like this) ---
**Author:** ![m.abumusa](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/m.abumusa/32/741_2.png) [@m.abumusa](https://forum.mautic.org/u/m.abumusa)\ **Post date:** [June 30, 2020, 5:28pm UTC](https://forum.mautic.org/t/unsubscribe-page-throws-error-500/14372/2 "2020-06-30T17:28:57Z")
Hello, Did you manage to know the cause of this error? I have exactly the same issue ---
**Author:** ![plato39](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/plato39/32/2343_2.png) [@plato39](https://forum.mautic.org/u/plato39)\ **Post date:** [July 13, 2020, 3:25pm UTC](https://forum.mautic.org/t/unsubscribe-page-throws-error-500/14372/3 "2020-07-13T15:25:10Z")
I have exactly the same error. I’m running Mautic 2.16.2 on PHP 7.3 ---
**Author:** ![joeyk](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/joeyk/32/11164_2.png) [@joeyk](https://forum.mautic.org/u/joeyk)\ **Post date:** [July 13, 2020, 6:50pm UTC](https://forum.mautic.org/t/unsubscribe-page-throws-error-500/14372/4 "2020-07-13T18:50:24Z")
In order to see what is the reason, you need to check the logs, why you get the 500 error. Check mautic log first. /app/logs I think. ---
**Author:** ![mayanktiwaridotcom](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/mayanktiwaridotcom/32/1501_2.png) [@mayanktiwaridotcom](https://forum.mautic.org/u/mayanktiwaridotcom)\ **Post date:** [April 27, 2021, 5:50pm UTC](https://forum.mautic.org/t/unsubscribe-page-throws-error-500/14372/5 "2021-04-27T17:50:04Z")
Anyone has any ideas why this is happening ? I am running Mautic 3.0.1 with php 7.4 and still facing the issue, error logs shows this: 2021-04-27 12:45:18] mautic.CRITICAL: Uncaught PHP Exception Twig\Error\LoaderError: “Unable to find template “:stnewsletterv2:base.html.twig” (looked into: /var/www/mautic/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /var/www/mautic/vendor/symfony/twig-bridge/Resources/views/Form).” at /var/www/mautic/themes/blank/html/message.html.twig line 1 {“exception”:"[object] (Twig\Error\LoaderError(code: 0): Unable to find template “:stnewsletterv2:base.html.twig” (looked into: /var/www/mautic/vendor/knplabs/knp-menu/src/Knp/Menu/Resources/views, /var/www/mautic/vendor/symfony/twig-bridge/Resources/views/Form). at /var/www/mautic/themes/blank/html/message.html.twig:1)"} ---
**Author:** ![mayanktiwaridotcom](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/mayanktiwaridotcom/32/1501_2.png) [@mayanktiwaridotcom](https://forum.mautic.org/u/mayanktiwaridotcom)\ **Post date:** [April 27, 2021, 6:15pm UTC](https://forum.mautic.org/t/unsubscribe-page-throws-error-500/14372/6 "2021-04-27T18:15:59Z")
In My case i found the issue, it seems like the default message display of the unsubscribe page tries to find the base and message.html.twig in the theme directory of the email in use, so even if there is no page.html.twig the base.html.twig and message.html.twig file is required else the unsubscribe page comes out to be broken. Hope this helps someone in future. ---
**Author:** ![joeyk](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/joeyk/32/11164_2.png) [@joeyk](https://forum.mautic.org/u/joeyk)\ **Post date:** [April 28, 2021, 11:00am UTC](https://forum.mautic.org/t/unsubscribe-page-throws-error-500/14372/7 "2021-04-28T11:00:07Z")
Hi, was it a custom theme or a mautic theme? ---
**Author:** ![mayanktiwaridotcom](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/mayanktiwaridotcom/32/1501_2.png) [@mayanktiwaridotcom](https://forum.mautic.org/u/mayanktiwaridotcom)\ **Post date:** [April 28, 2021, 11:13am UTC](https://forum.mautic.org/t/unsubscribe-page-throws-error-500/14372/8 "2021-04-28T11:13:40Z")
It was custom theme.