Apps are disabled on this site.

Error:

 ErrorDetail: Apps are disabled on this site.
        ErrorType: Configuration
        ErrorTypeName: Configuration
        ExceptionMessage: Microsoft.SharePoint.SPException: Apps cannot be installed. Review the diagnostic logs for more details regarding app deployment failures.
   at Microsoft.SharePoint.Utilities.SPUtility.ThrowSPExceptionWithTraceTag(UInt32 tagId, ULSCat traceCategory, String resourceId, Object[] resourceArgs)
   at Microsoft.SharePoint.Packaging.SPUserCodeSolutionDeploymentGroup.Deploy()
   at Microsoft.SharePoint.Administration.SPAppTask.DeployOperation()
   at Microsoft.SharePoint.Lifecycle.MonitoredTaskExecution.DoTask()
        Source: AppWeb
        SourceName: App Web Deployment
Error occurred in deployment step 'Install app for SharePoint': Failed to install app for SharePoint. Please see the output window for details.


Reason:
You will get this error when you are trying to deploy your SharePoint 2013 "app" through visual studio.The reason behind this error is you might not created the "App domains" for your application.

Solution:
To create the "App domain",  please refer my another post in the below URL:

http://sensoft2000-sharepoint.blogspot.in/2014/10/the-subscription-settings-service-and.html


Thats it...

Error occurred in deployment step 'Uninstall app for SharePoint': The local SharePoint server is not available. Check that the server is running and connected to the SharePoint farm.

Error:
Error occurred in deployment step 'Uninstall app for SharePoint': The local SharePoint server is not available. Check that the server is running and connected to the SharePoint farm.

Reason:
some of the core databases in your SharePoint SQL server does not have the enough access rights for the "currently logged-in" user. You must provide "db_owner" for them.

Solution:
You need follow the steps which i was published in the year 2011.
URL: http://sensoft2000-sharepoint.blogspot.in/2011/07/error-occurred-in-deployment-step.html


Thats it...

Cannot connect to the SharePoint site: http://MachineName:5000/sites/xyz/. Make sure that the Site URL is valid and that the current user has the necessary permissions to access the site.

Errors:

---------------------------
Microsoft Visual Studio
---------------------------
SharePoint Connection Error

Cannot connect to the SharePoint site: http://MachineName:5000/sites/dev/. Make sure that the Site URL is valid and that the current user has the necessary permissions to access the site.

Additional information:

"The remote server returned an error: (500) Internal Server Error."


(Or)

---------------------------
Microsoft Visual Studio
---------------------------
SharePoint Connection Error

Cannot connect to the SharePoint site: http://MachineName:5000/sites/dev/. Make sure that the Site URL is valid and that the current user has the necessary permissions to access the site.

Additional information:

"Cannot contact site at the specified URL http://MachineName:5000/sites/dev/."


Reason:
You might have provided entry to that SharePoint server in your "hosts" file. The "hosts" file will be under "c:\windows\system32\drivers\etc".

Solution:
1. Go to that folder and edit the "hosts" file in Notepad and remove the "mapping" for that server.
2. Reset the IIS.
3. Close and re-open the Visual Studio 2012.
4. Now create the Solution in Visual Studio and you will not see this error.

That't it....