Browser Login Window showing up

Everytime I have cleaned the Solution and start the page for the first time, it shows that I am not logged in
and will prompt me a window from the browser that orders me to log in into the page.
but the browser window will not take my credentials. It will just prompt again and again.
So I cancel the window and try login on the html page as it should be.
The login on the html page won't work either although it shows in the code it clearly runs successful through.
After the function it will just show up with login page again.

When I stop the debugging and the run the solution again, it will show me as logged into the page.
Does anybody know how to solve this?

Oh and I have Version 3.80 running

The page is acting totally weird. I tried to deploy to an IIS 7.5 Webserver Windows 2008 R2

When I delete my plugin from the plugin folder the page will let me log in.
When I add my plugin afterwards (without logging out) it will all run fine.
When I log out of the system I get an error 401 unauthorized...

I don't even know where to look anymore :-(

Is this similar to?

Always redirect to login page  

And

homepage redirect me to login?ReturnUrl=%2f (Error)

I found out it had something to do with the Controller,
but I do not get to understand the exact reason why.

I have a widget that loads special topics created by my plugin.

My function was in a Controller that provides Actions for Adminarea
I moved the Actions for public area to another controller and now the issue seems to be gone.

The Controller providing Actions for Adminarea looks like this:

 [PublicStoreAllowNavigation(true)]
    [NopHttpsRequirement(SslRequirement.No)]
    public class DDSAboProductPageController : BaseAdminController, IController
    {
        [PublicStoreAllowNavigation(true)]
        public  ViewResult Topic(int topicId)
        {....}

}

This is the one I moved the actions now to:

    public class AboTicketSystemController : BasePluginController

public  ViewResult Topic(int topicId)
        {....}
    {

I gather it might be because of being a "BaseAdminController"
If so I would appreciate if somebody could confirm and maybe explain that to me.
I am not totally familiar with the restrictions and securitymodel here.

Are Methods of an Admincontroller restricted to the "administrative" Area only?