Getting unexpected error when adding columns to a list or a Doc Library in SharePoint 2010

I am getting an unexpected error (see below) when I try to add a column to a list.

Error An unexpected error has occurred.

Troubleshoot issues with Microsoft SharePoint Foundation.

Correlation ID: 6efebddc-675d-43fd-8754-43cea59908b7

Date and Time: 08/24/2011 12:06:16 PM

From the SharePoint log I have found the below details.

06:16.8 w3wp.exe (0x01A8) 0x1080 SharePoint Foundation Runtime tkau Unexpected System.ArgumentNullException: Value cannot be null. Parameter name: s at System.IO.StringReader..ctor(String s) at Microsoft.SharePoint.ApplicationPages.ManageFieldPage.ProcessList() at Microsoft.SharePoint.ApplicationPages.ManageFieldPage.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean开发者_JS百科 includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) 6efebddc-675d-43fd-8754-43cea59908b7

I have two front-end Web servers, two databases and one application server. Does it have anything to do with alternate access mappings (AAM) as it's accessible through the Internet using HTTPS?

To find out more information about the error you need to look in the SharePoint log for the errors/warnings associated with the Correlation ID. Try using a tool like ULSViewer found here http://archive.msdn.microsoft.com/ULSViewer/Release/ProjectReleases.aspx?ReleaseId=3308.

1. Start ULSViewer and have it start to monitor the SharePoint Log file.
2. Once ULSViewer is populating with log entries perform the activity that is causing the error.
3. Pause ULSViewer and then filter by the Correlation ID. This will give you a better idea of what is failing and possibly why.

It was an AAM issue. My host name was not mapped to HTTPS, and after mapping it to HTTPS the error is gone,

http://myhostname -> https://myhostname