While skinning a DNN site I have encountered the following error:

An error has occurred.
DotNetNuke.Services.Exceptions.PageLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Common.Globals.CreateValidID(String strID) at DotNetNuke.UI.Skins.Controls.Styles.AddStyleSheet() at DotNetNuke.UI.Skins.Controls.Styles.Page_Load(Object sender, EventArgs e) at System.Web.UI.Control.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---

It happened when I went to preview my skin, but now I can't get back to the  site at all!!! There is a button (Return to Site) but it wont work, just keeps loading the error.
There was an error in my .xml file when I went to preview the site, (I had missed a line of code).. so I fixed it and when I hit preview, it just errored.. and now I cant get rid of the error to get back to my site!! This happened once before and I reset the whole site! I dont want to have to do this again.. is there a manual way to fix this!?