When I open Central Administration I get this error
HTTP Error 503. The service is unavailable.
Same error also when I open my SharePoint Server 2010 site
HTTP Error 503. The service is unavailable
How to resolve this?
When you run into the issue “HTTP Error 503, the service is unavailable” when you launch the website through IIS (Internet Information Services), you will end up seeing the following message:
To remediate the issue, you will need to open IIS Manager (inetmgr.exe). This error is caused because specific website Application Pools were stopped or disabled by a certain circumstance. You will need to select the Application Pool, for the affected Web Applications, and hit Start. Once completed, please revisit your web application.
Note: If the application pool continues to stop, please verify that all SharePoint services are started, this error might occur because of changing the service account password. You may need to change the new password for the application pool or sharepoint timer service.
[ Source ]
Please, ensure, that the IIS application pools that belong to these SharePoint web applications are up and running. If they are running, you can try to restart them.
Often it happens as you install a new solution into the SharePoint farm. Most of the time this issue is only temporary (1-2 Minutues), but can be quite frustrating.
See this post as reference.
Goto IIS manager ->Application Pool, click stopped application pool like 'SharePoint Central Administration v4' Right click Advanced settings, and set "Enable 32-bit applications" to "False"
More info https://social.msdn.microsoft.com/Forums/office/en-US/c960aa7f-e7dc-4400-9067-377e8d537c90/service-unavailable-http-error-503-application-pool-stopped-for-the-web-appliaction?forum=sharepointdevelopmentprevious
Click the stopped application pool -> click advanced settings ->Identity ->click the user to retype the user ->Application Pool Identity dialog ->click set -> manually type the user name and password. Then restart the server.