If I uncomment the ASKBOT_EXTRA_SKINS_DIR settings the model validation just stalls never to recover again until i recomment the setting.
Create the directory indicated by ASKBOT_EXTRA_SKINS_DIR (for example: skin/my_askbot). This directory must have the same structure as static/common or static/default (ie: countains the directories media and templates). The files in your skin directory will override the files of common and default.
In settings.py add STATICFILES_DIRS = (os.path.join(ASKBOT_ROOT, 'skins'), ASKBOT_EXTRA_SKINS_DIR)
Finally, in your site, log you as root user and in settings->Logos and HTML <head> parts choose the name of your skin.
Comments
Does the directory exist?
Please give a snippet of settings that leads to the error, we might improve the settings validator based on your input.