unable to log in to the account

Question

Hi,

I am currently doing an internship in a company that specializes in IT security.

First of all, I should do a little stuff with virtual machines so that you can see my status. I've recently been working with another intern to set up a relatively simple environment that will also be used for pentesting, but I came across two problems that aren't actually that important, especially for a virtual test environment, but I would do things like that in a real one Avoid, but still can't find a solution after several hours of Googling and watching videos. If anyone could help, I would be very happy.

Problem 1

When sharing folders via a file server, I don't get hidden folders from users who don't even have read rights. You set "if released via the server manager" an option to tick which explicitly states that folders to which users or groups do not have permission to at least read them will be hidden. Nevertheless, they are always displayed, although they are still displayed without the permissions of certain users, although they actually shouldn't be there.

Problem 2

A little more complex, I created users directly in the domain controller, set all standard permissions, remote desktop via gpo, etc. correctly. But when I log in to a client (already included in the domain) with a domain user, I always immediately get the message "unable to log in to the account", and I get a TEMP profile, no matter which user, no matter what level (user, admin, etc ). Now I can't figure out how to solve this problem at the domain level. I've seen at least 20 videos and quite a few articles about this problem, but they all still don't give a good solution. Some say you should use the MMC - local users and groups to create the user on the client and restart it, others say you have to adjust a registry entry, delete the duplicate entry and rename the remaining one that ends with .bak... those are for me no solutions because they are only on one client. If I have 50 PCs I would have to access all 50 and make adjustments for each individual user. This has to work at the domain level too, perhaps with a gpo or something, right? or most importantly, can someone explain to me exactly how this problem occurs, i.e. why? I can't find any explanation about what exactly causes this problem, just copy paste solutions that say the same thing as already mentioned, which doesn't help.

Sorry for the long text, and thanks to everyone who reads it and has a possible solution or suggestion ^^ and Sorry for bad EN, im not a EN speaker.