Export Farm Solution Package with PowerShell

Follow the steps below to export a farm solution package…

1. Open a text editor – such as Notepad.
2. Paste the following code snippet:

$farm = Get-SPFarm
$file = $farm.Solutions.Item("MySolutionPackage.wsp").SolutionFile
$file.SaveAs("c:\MySolutionPackage.wsp")

3. Replace the highlighted text above with the name of your solution package.
4. Save the file - give the file a name and save it with the extension ps1 (eg. extract.ps1) and place the file on the C:\ drive.
5. Open the SharePoint 2010 Management Shell
6. Navigate to the location of the script and execute it.
7. The solution package will be available on the C:\ drive

Update: If you want to download all the solutions at once you can use the following script:

$dirName = "C:\Solutions"
foreach ($solution in Get-SPSolution)
{
$filename = $Solution.SolutionFile.Name
$solution.SolutionFile.SaveAs("$dirName\$filename")
}

Error: The form cannot be rendered. This may be due to a misconfiguration of the Microsoft SharePoint Server State Service...

This error can be encountered while viewing an InfoPath form in the browser. In most cases, the problem can be solved by reading through the following blogpost.

In my case, the state service was enabled and the service application was correctly associated with the webapplication. I solved this by deleting the 'corrupt' state service database, creating a new one and attaching the new database to the farm - all these steps can be done with some Powershell commands.

Remove-SPStateServiceDatabase
New-SPStateServiceDatabase
Mount-SPStateServiceDatabase

Related article: Manage the State Service (SharePoint Server 2010)