The problem starts when Microsoft SharePoint Online site enables full access permissions to some users, but when they have tried to access the site settings, following error message occurred.

Error: ‘Access Denied.’

Access Denied
In order to resolve this issue when the users browse to the Access Requests list and select Approve or Decline for a pending request, then again a new error message occurred:
‘Sending approval’
‘Request approval failed’

Causes
In order to describe the problem, first you need to figure out the symptoms. Following are the scenario you can consider that leads the above explained share point error:

If you are using the following version of Microsoft SharePoint

  • Microsoft SharePoint Server 2010
  • Microsoft SharePoint Foundation 2010
  • Microsoft Office SharePoint Server 2007

You have re-created a user account in Active Directory Domain Services after delete and then again add the newly created user account to the SharePoint server.

Description:
Basically error: ‘Access Denied’ occurs, when you add an existing user’s information inthe SharePoint and it updates the existing entry in the UserInfo table instead of creating a new entry. Where the user security identifier (SID) in the old entry has already updated and is no longer correct for that particular user.

Solution:

  1. In order to resolve this issue, you can use an inbuilt tool named as ‘MigrateUser’ tool that is used to add the new user account to SharePoint. Follow the below mentioned steps to complete this process:
  2. Go to the server that is running SharePoint, Select Start -> All Programs, and then Accessories.
  3. Now, right-click Command Prompt, select Run as Administrator from the available options. Now, click ‘Yes’.
  4. Type the below mentioned command in the command prompt, and press ENTER:
    ‘stsadm.exe -o migrateuser -oldlogin Domain name\Old user name -newlogin Domain name\New user name –ignoresidhistory’

Note:This command can be used only on user accounts that are in the same domain elseit might create permission issues. MigrateUser command will automatically update the account name and also maintains the appropriate permissions for the targeted account.

Some other solutions:

  • Possibly some of the services on your server are shut down, which are causingissues with the Search index distribution. Check out all the server permissions and enable the required one if needed.
  • If someone has changed the permissions on the site assets library then also such kind of errors occurs. To resolve this you can check the permissions on Document library, “Site Pages” library or something similar on the same site that might create such type of trouble. As at times,due to broken inheritance on the Doc Library become the root cause of the error.

In case while trying the above explained processes your SharePoint data got corrupt and become inaccessible then instead of trying manual methods, it is better to go with professional software as these tools are dedicatedly designed to repair SharePoint data without any risk of data loss. Stellar Phoenix SharePoint Recovery is a reliable example of professional SharePoint Server Recovery software that repairs you corrupt and damaged SharePoint databases or SQL Server files and restores all the important information from SharePoint Server.