Admin Panel 404 Error

[FelipeA3]

Hello!

I'm facing an issue with a Magento 2 website.

When I try to go to the admin panel page, "atacadovariedades.com.br/magento2/admin", the website shows me the 404 error.

At the error_log, I got the following message:

[28-Mar-2018 11:48:31 UTC] PHP Fatal error:  Class 'Zend_Cache_Backend_File' not found in /home/wwwatacadovaried/public_html/magento2/vendor/colinmollenhour/cache-backend-file/File.php on line 39

Can anyone help me with this issue?

[Yogesh Sharma]

try following

composer dumpautoload -o

and then

./bin/magento setup:di:compile

clear magento cache and then try again

[FelipeA3]

Where can I perform these commands? Sorry I am a complete newbie at Magento 2.

[Sourabh Modi]

You will have to SSH to your server and go to root directory of your server.

when you reach to your projects too just run below commands and it should work or what ever you want to run

php bin/magento cache:clean
rm -rf var/cache/*
rm -rf var/generation/*

[FelipeA3]

I can't do it. I was informed that my server account type doesn't allow it.

Is there an alternative?

I really appreciate the help.

[FelipeA3]

I can't do it. I was informed that my server account type doesn't allow it.

Is there an alternative?

I really appreciate the help.

[Rakesh Jesadiya]

You need to run compilation command from SSH and you must have to access for your server to run compilation command.

run from your magento root, 

php bin/magento setup:di:compile

You can clear cache from Backend panel, But your backend panel is not working so you have only way to clear cache using command.

php bin/magento cache:flush