You need to be a site collection administrator to set this property.

Issue Description

Recently I was trying to add a site collection administrator to a site and I got the belowmessage

You need to be a site collection administrator to set this property.   at Microsoft.SharePoint.ApplicationPages.ManageSiteAdminPage.BtnSubmit_Click(Object sender, EventArgs e)

   at System.Web.UI.WebControls.Button.OnClick(EventArgs e)

   at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)

   at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)

   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

I was already the site collection administrator to the site and it did not make any sense.

Fix

On further trouble shooting, I found the solution for this.Browse to Central Administration - > Site Collection Quotas and Locks.

The options available here are:

       Not locked

Adding content prevented

Read-only (blocks additions, updates, and deletions)

No access

This site collection was in Read-only status. Unlock it (Change the status to  "Not Locked")

How to change the URL for SharePoint Central Administration site

If you extend the Central Administration web application (using GUI or psconfig command) to run on multiple servers, and when you click on SharePoint Central Administration icon you're still redirected to the first SharePoint server where Central Administration is hosted.

The URL has to be changed via registry on all SharePoint servers to fix this.

To change the URL for SharePoint Central Administration URL:

1) Open Registry editor

2) Backup the registry before making changes

3) Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\14.0\WSS and change the value of CentralAdministrationURL to the new URL