Magento 2.2.6 Pasket Error

[AbrahamJ]

Hello everyone, I'm new to Magento. I installed Magento 2.2.6. 
It is not added to the basket after login. But If you are not login you can add items to the basket. It' error: We can't add this item to your shopping cart right now. Thank you.

[gelanivishal]

Hello @AbrahamJ,

I have experienced very same situation, and it was because of 2 things mainly.

1. The write permission for the generated folder.
2. Still there was an issue with folder owner. The generated folder was under the ownership of root. When I changed that to Apache user, everything went smooth.

--
If my answer is useful, please Accept as Solution & give Kudos

[AbrahamJ]

Thanks for your answer. Can you detail subject.

[theMageComp]

Hello @AbrahamJ

Check magento log file for detail description of error and try to solve that error.

[AbrahamJ]

I looking at the right place?   
var/log/system.log

and I don't understand, what is the problem?

[AbrahamJ]

I'm taking the following error, what am I supposed to do? Please.
Thanks

exception.log 

[2018-10-22 11:03:47] main.CRITICAL: Validate class not found from basename 'Magento\Framework\Validator\EmailAddress' {"exception":"[object] (Zend_Validate_Exception(code: 0): Validate class not found from basename 'Magento\\Framework\\Validator\\EmailAddress' at /var/www/vhosts/*******.com/httpdocs/vendor/magento/zendframework1/library/Zend/Validate.php:244)"} []

[AbrahamJ · Accepted solution]

Thanks everyone. I solved the problem.
Prolem with the PLESK PHP seetings. Plesk includes per default some wired zend directories ..
In the option "include_path"

After i switched the include path to "." it works.

SOURCE : PhiIipp commented on 5 Oct 2017
https://github.com/magento/magento2/issues/10821#issuecomment-333397261