Why can't I edit, delete, add, or upload any files in the file manager?

Now I know how these problems happen. And at that moment, this problem I am suffering from occurred.

I did this before this problem happened to me.

Because default perms for dir /home/user/web/domain/ are 551 and that means your user don’t have write perms to that dir.

You can add write perms for your user using this (keep in mind that this will affect all your users and domains):

Note: replace YourUser and YourDomain by the actual data.

v-change-sys-config-value DOMAINDIR_WRITABLE yes
v-rebuild-web-domain YourUser YourDomain

Then the problem happened.
Here is the link