Error when Deploying Solutions in SharePoint using stsadm - "The farm is unavailable" and "Object reference not set to an instance of an object."

If you receive errors when Deploying Solutions in SharePoint using stsadm - such as "The farm is unavailable" and "Object reference not set to an instance of an object.", then you have a permissions issue.

You will typically get errors like this when running stsadm commands such as those found in this PowerShell script snippet below:

if ($isValidConfig -eq "true")
{
 Write-Host "Retracting Solution -  SERVER:$computer, SITE:$siteUrl" -Fore DarkGreen
 stsadm -o retractsolution -name SolutionName.wsp -immediate -url $siteUrl
 stsadm -o execadmsvcjobs
 Write-Host "Deleting Solution -  SERVER:$computer, SITE:$siteUrl" -Fore DarkGreen
 stsadm -o deletesolution -name SolutionName.wsp -override
 stsadm -o execadmsvcjobs
 Write-Host "Adding Solution -  SERVER:$computer, SITE:$siteUrl" -Fore DarkGreen
 stsadm -o addsolution -filename SolutionName.wsp 
 stsadm -o execadmsvcjobs
 Write-Host "Deploying Solution -  SERVER:$computer, SITE:$siteUrl" -Fore DarkGreen
 stsadm -o deploysolution -name SolutionName.wsp -url $siteUrl -immediate -allowgacdeployment -force
 stsadm -o execadmsvcjobs
 Write-Host "Activating Feature - SERVER:$computer, SITE:$siteUrl" -Fore DarkGreen
 stsadm -o activatefeature -name FeatureName -url $siteUrl -force
 stsadm -o execadmsvcjobs
 Write-Host "OPERATION COMPLETE - SERVER:$computer, SITE:$siteUrl" -Fore DarkGreen
 stsadm -o execadmsvcjobs
 Write-Host "Resetting IIS so we avoid 'Unknown Error' or 'File Not Found' errors - SERVER:$computer, SITE:$siteUrl" -Fore DarkGreen
 iisreset
 stsadm -o execadmsvcjobs
}

Errors that occur with the script if you don't have correct permissons on the SharePoint configuration database:

You should have dbo permissions to the Configuration database for your farm. See my related article for details on the permissions you need for solution deployment - http://ddkonline.blogspot.com/2010/03/list-of-permissions-required-for.html

DDK