Getting Unable to serialize value after upgrade magento to 2.2.5

Question

I am getting following error when I open any parent category page after upgrade Magento to 2.2.5

1 exception(s):
Exception #0 (InvalidArgumentException): Unable to serialize value.

Exception #0 (InvalidArgumentException): Unable to serialize value.
#0 /media/emipro/ssd_drive/mage2/navoco/vendor/magento/framework/App/PageCache/Kernel.php(153): Magento\Framework\Serialize\Serializer\Json->serialize(Array)
#1 /media/emipro/ssd_drive/mage2/navoco/vendor/magento/module-page-cache/Model/Controller/Result/BuiltinPlugin.php(96): Magento\Framework\App\PageCache\Kernel->process(Object(Magento\Framework\App\Response\Http\Interceptor))
#2 /media/emipro/ssd_drive/mage2/navoco/vendor/magento/framework/Interception/Interceptor.php(146): Magento\PageCache\Model\Controller\Result\BuiltinPlugin->afterRenderResult(Object(Magento\Framework\View\Result\Page\Interceptor), Object(Magento\Framework\View\Result\Page\Interceptor), Object(Magento\Framework\App\Response\Http\Interceptor))
#3 /media/emipro/ssd_drive/mage2/navoco/vendor/magento/framework/Interception/Interceptor.php(153): Magento\Framework\View\Result\Page\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Response\Http\Interceptor))
#4 /media/emipro/ssd_drive/mage2/navoco/generated/code/Magento/Framework/View/Result/Page/Interceptor.php(130): Magento\Framework\View\Result\Page\Interceptor->___callPlugins('renderResult', Array, NULL)
#5 /media/emipro/ssd_drive/mage2/navoco/vendor/magento/framework/App/Http.php(139): Magento\Framework\View\Result\Page\Interceptor->renderResult(Object(Magento\Framework\App\Response\Http\Interceptor))
#6 /media/emipro/ssd_drive/mage2/navoco/generated/code/Magento/Framework/App/Http/Interceptor.php(24): Magento\Framework\App\Http->launch()
#7 /media/emipro/ssd_drive/mage2/navoco/vendor/magento/framework/App/Bootstrap.php(256): Magento\Framework\App\Http\Interceptor->launch()
#8 /media/emipro/ssd_drive/mage2/navoco/index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http\Interceptor))
#9 {main}

I have checked many links many similar issues in stack overflow and git but nothing works.

I have upgrade Magento from 2.1.10 to 2.2.5

This error only comes when I open the parent category page. Sub-category page working well.

Update :

Now error is coming randomly, like sometimes we hard refresh then error will display in any page.

Please share the solution / suggestion if anybody have an idea.

Thanks.

Answer 1

For me this issue is coming because of some glitch in my html.

Like following html was not rendering properly. So i remove it and now its working fine for me.

<a href="javascript:void(0)" class="closebtn">×</a>

Here × is not rendering properly in html. So i changed it with X;