I am completely new to DNN and skinning, and in my first experience working with tweaking a skin, I made changes to the html & CSS of a skin... using only left and right panes. After I  uploaded the new skin (whilst logged in as host) the drop down menu items for admin and host appear, but none of the pages come up.  I suspect the content of these pages is all in the content pane, which I ignorantly removed from the html, hence nothing appears in those pages.

Since I would like to revert to the DNN-Blue default skin, but can't get to the menu to do so, I'm wondering how I might be able to do this easily without the page interface. Also, a child site of the portal is operating okay, so can I somehow affect the parent's skin via the child???

Additionally, none of the login options of the child sites work at all, now; either. I'm completely stuck in the mud! The error message on the children sites is:

A critical error has occurred.
Object reference not set to an instance of an object.

I appreciate any assistance you can provide!

Thank you. I guess this is part of the learning process: I'll certainly take your advice and not play with portal skins ever again!

Your suggestion has helped me to resolve one error; but now I'm still unable to login and I get the error message:

A critical error has occurred.
Object reference not set to an instance of an object.

I think I caused this by attempting to clean up some of the preliminary skins I had uploaded during my learning process. I had applied the "winter" skin that I got from Chapter 3 of the DNN Skinning book, and after I modified the css and html files, I renamed the zip file winter1, winter2, etc. I kept the winter.css .htm and .xml names and I had gotten to winter4.zip when I began to clean up (from the ddn interface) the older skins. The problem is that I deleted the original winter skin from the interface side, and I think something is looking for (and not finding) it - even tho the skin upload page referenced winter4.

Is there some way to set the portal back to dnn-blue without using the skin interface? If so, then I can just use a child site to experiment and learn with.

Sorry for the lenghty explanation, and thanks for your help!

Thanks for your help. I removed all references to my skins in all the directories listed above, backed up the web.config file and modified it, and now I get the following runtime error. I even backed out of the web.config file change and this error persists. I'm running DNN 4.7 online, and have been making the changes to my online portal. Also, the " " that you suggest making in the first line of web.config should look like: <configuration " ">  or should the " " go somewhere else? Anyway, here's the latest error message that I'm now getting at the portal and all children levels. THANKS for any help you can provide.

Server Error in '/cd' Application.

---

<!-- Web.Config Configuration File -->

<configuration>
    <system.web>
        <customErrors mode="Off"/>
    </system.web>
</configuration>

<!-- Web.Config Configuration File -->

<configuration>
    <system.web>
        <customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"/>
    </system.web>
</configuration>