Receiving Blank Page or Access Denied on Magento System - Configuration Page

If you have installed an extension or trying to open a page on your Magento Admin > System > Configuration area, then you might get a blank page or a page saying, “Access Denied”.

Fix :

Goto Magento admin > System >Permissions > Roles
You will see one item there with name, “ADMINISTRATORS”.
Click on it once and without doing any changes, just save.

That will reset the permissions automatically and you will be able to see everything in the right manner, rather than getting any blank page or access denied message.