Application pool keeps stopping / Service Unavailable / 503 errors in SharePoint Site


This issue is faced so many times. Every time someone changes a password for a service account, it keeps prompting errors when we open the site. So, we thought to share this useful info with those who face the same issue.



Changing of password for the Application Pool account.



Solution 1:

To change\check the identity for an application pool, log into Central Administration and follow these steps.

Changing application pool id in IIS is the recommended way.

  1. Select the application pool from the components drop-down.
  2. Select the managed account that you want to use as the identity for this application pool, or register a new managed account in SharePoint 2010 using the Register a new managed account link.
  3. Click the OK button.

You’ll be warned that this action requires an IIS reset on all servers, click OK. Perform iisreset /no force on all WFE servers in the farm.

If the above doesn’t resolve the issue:

Solution 2:

If you check the eventvwr, you will find a logged error in it:

Error: “The Module DLL 'C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\isapi\owssvr.dll' could not be loaded due to a configuration problem. The current configuration only supports loading images built for a x86 processor architecture “Please follow the below steps to overcome the issue.

  1. Open IIS by typing inetmgr in Run.
  2. Click on Application pools.
  3. Click on the particular Application pool for your site.
  4. Right-click Advanced settings.
  5.  Set Enable 32-Bit Applications to False.


Solution 3

Manually put the changed PWD in the Application Pool. Perform an IIS reset.

App pool -> advanced settings ->

See more at:

Note: If you find a different solution, please report it as a comment to this post. This will be useful to the SharePoint Community. Be sure to double-verify it: undo your solution and verify that the problem comes back, then redo it and verify that the problem goes away.

See Also

  1. SharePoint Resources on the TechNet Wiki
  2. SharePoint 2013 Portal
  3. SharePoint 2013 - Service Applications
  4. SharePoint 2013 - Resources for Developers
  5. SharePoint 2013 - Resources for IT Pros