Yes, sorry I copied the path from the install package not the actual install.

To be honest the only thing that could help is to start to replace things step by step to find out what the problem is.

The error is about the default skin it seems (but it might be something the skin loads too)

If you can, copying the installation to a local machine and start from there.

Also do a fresh install next to the problem DNN.

First I would try all the skins on a fresh install including the default skins.

Then copy stuff from the working new install to the problem install, untill it works..

I hope you find the problem, there is not much more I can suggest..

Timo:

I know this is an old thread but I just found it while researching the same exact problem.  This may help others who find this thread.

In my case, I found (with the use of the SysInternal's tool Process Monitor) that my site (DNN 4.9.5)  was reading the Dotnetnuke.config file from the root of the site and not from the /config/ directory.  In fact, there was a Dotnetnuke.config in the /config/ directory, with the correct entry for skinningdefaults, but the file on the root of the site was missing the entries.  As soon as I added the entries to the file on the root of the site the Skin management option started working just fine.  I monitored this process after doing an IISReset and by the way, the file in the /config/ directory was never accessed.

Is this the way it is supposed to be???

Carlos