Today I had the same problem again. I think something goes wrong in the database. The page had a similar skin applied to it and worked all the time and at once (while changing to a skin that does work on other pages) I got the 404 Error again.
Only for this page.
I decided to have a look at the differences with other pages in the database, and while trying this solved the problem for this page (only)

I opened admin > pages.
Selected the page
Choose "edit selected page" (the pen)
Clicked update without changing anything and the page functioned correctly again.

I think this is a better solution then deleting the page and create a new one.
Anyway, I'm convinced it's a bug, not a problem in the skin.
(I didn't make a database backup before trying to repair the page, so I'll have to wait for the error again, stupid.....)

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I'm have the same problem again, this time with DNN 3.3.4, but I think I found the reason.

I have had the same problem a few times now and mostly solved it by deleting the page and recreating it, but since it's still happening once in a while I wanted to solve it / find the problem.

I created a skin with <img src="<%= SkinPath %>blahblah> in it.
I have a page that has the skin applied to it, it works fine.
If I try to apply the skin to another page I sometimes got the following error, now I get it for every new page.


Normally if there is a problem with a skin you get a DNN error, but this seems to be a .NET error caused by the skin.

Even if I put only in the skin I get the error.
If I strip out the line with the <%= SkinPath %> there is no problem.

Now I found out that in some cases (but not always) you get this Error if there is no Contentpane called "contentpane" in the skin, in combination with a <%=skinpath %>
If I add one the problem is gone.

It seems that the combination of DNN not finding the ContentPane it wants with a <% =SkinPath%> in the Skin causes the error.

Conclusion:
Add a pane with "id=ContentPane" to your skin and your problems are solved....

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Okay, I agree it's well documented and you cannot call it a bug.
But people do make (stupid) mistakes (if you base one skin on another like I did it's easy).
And the server error makes you think you DNN installation died.
DNN gives you a nice error message for everything that's why it took me such a long time to see where (my stupid) mistake was.

I personally think it would be an enhancement if the skinpath wouldn't hide the contentpane error message, but you probably don't agree.

Well I just hope this post will help other people who made the same mistake.
I'll change my first post so they don't have to read verything

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