After Successful Installation Magento Getting Blank Gray page for Admin

[gregopante3d50]

Worked for me as well.

I had a similar error after successful installation with cmd line.

My error was:

Spoiler

1 exception(s): Exception #0 (Exception): Warning: Use of undefined constant fileDriver - assumed 'fileDriver' (this will throw an Error in a future version of PHP)  [....] Validator.php on line 139

[eiduladhaw6106]

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@Shofiul wrote:

Dear @kanhaiya5590 

Excellent job. All other sollution explained by others member is really just wasted my time. Specially after successful installation of magento 2.3.0 if any one see blank gray admin login page. You just follow the above solution. Do not need to anything else. All other explanation For example - running command as below is just wasting your time, such as

php bin/magento setup:static-content:deploy -f 

php bin/magento setup:upgrade

all these are nothing to do with this problem or anything about permission. 

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This is what is miss. Thanks for that help.