I don't know what I did, but I can NOT upload any files or do anything in the Admin File Manager.  When I go into the Admin File Manager there is a little yellow triangle with an exclamation point in the lower left corner of the Browser Window. 

If I click on Upload Files, this is the error that I get:

A critical error has occurred.
Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

Does anyone have any clue as to what this means?  What dumb thing could I have done to cause this.  I am NEW to DNN, but have been learning and have been experimenting with DNN 3.2.2.

PLEASE HELP!

THANKS IN ADVANCE FOR ANY SUGGESTIONS!

Nadine

Thanks for the info.  I went to the URL you suggested and tried to implement the fix described there.  However, File Manager is still not functioning properly.  It still loads it "with errors".  There is a Yellow triangle with an exclamation point in the lower left corner of the browser windows that says "DONE, but with errors on page".

However, after I instituted the above fix, the File manager acts like it is letting me upload a file, but the file does not show up in the list.

Does anyone have any other suggestions?

Nadine

This is the error I get when I try to (from the Admin Skins page) upload a new skin the I downloaded.

Error: File Upload is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Cannot access a closed file. ---> System.ObjectDisposedException: Cannot access a closed file. at System.IO.__Error.FileNotOpen() at System.IO.FileStream.Seek(Int64 offset, SeekOrigin origin) at System.Web.HttpRawUploadedContent.TempFile.GetBytes(Int32 offset, Int32 length, Byte[] buffer, Int32 bufferOffset) at System.Web.HttpRawUploadedContent.CopyBytes(Int32 offset, Byte[] buffer, Int32 bufferOffset, Int32 length) at System.Web.HttpInputStream.Read(Byte[] buffer, Int32 offset, Int32 count) at ICSharpCode.SharpZipLib.Zip.ZipInputStream.FillBuf(Int32 size) at ICSharpCode.SharpZipLib.Zip.ZipInputStream.GetNextEntry() at DotNetNuke.UI.Skins.SkinController.UploadSkin(String RootPath, String SkinRoot, String SkinName, Stream objInputStream) at DotNetNuke.Modules.Admin.FileSystem.WebUpload.cmdUpload_Click(Object sender, EventArgs e) --- End of inner exception stack trace ---

Any other ideas?

I AM DESPERATE!

Thanks in advance for everyone's help and time!

Nadine