Error occurred in deployment step ‘Retract Solution’: The language-neutral solution package was not found.

We sometimes get this error when deploying SharePoint 2010 solutions from Visual Studio 2010:

Error occurred in deployment step ‘Retract Solution’: The language-neutral solution package was not found.

To resolve this error user Powershell :

• Run Powershell.
• Ensure you have Sharepoint Powershell commands enabled
  For that run following command
  
  Add-PSSnapin Microsoft.SharePoint.Powershell 
• run following command (Replace mysolution.wsp with your solution name)
  (get-spsolution mysolution.wsp).Delete()