Feature Upgrade Issue: Deleted SPWebs : An error occurred while enumerating through a collection

Introduction

Recently I published a post about issues when upgrading Site Scope features in SharePoint. The issue was related to deleted Site Collections which were still in the recycle bin.
After resolving this issue I decided to do some testing with other deleted SharePoint objects. The next logical object type to delete was an SPWeb object.
Unfortunately further issues were found and the following section explains how they were found and the approach to resolve them.

How the Issue was Approached

The approach taken was the following:-

• Build a Web Scoped Feature marked v1.0.0.0
• Install the SharePoint Solution
• Create a number of Webs and Activate the feature on those webs
• Delete one of the Webs
• Update the Web Scoped Feature to v2.0.0.0
• Upgrade the SharePoint Solution to deploy the new version of the Web Scoped Feature
• Use Install-SPFeature [FeatureName] –Force to upgrade the feature
• Run a PowerShell command to execute the SPSite.QueryFeatures() function

The following PowerShell was run to query for Features that need to be upgraded.

$site=Get-SPSite http://sharepoint; $site.QueryFeatures("Web", $true);

The result of the script displayed the following:-

1

$site.QueryFeatures("Web",$true);  An error occurred while enumerating through a collection: Unable to access web scoped feature (Id: f41cc668-37e5-4743-b4a8-74d1db3fd8a4) because it references  a non-existent or broken web (Id: 3bd828cf-b747-4111-b888-5953b0d9aaa3) on sit e 'http://dev.itsp.local'.  Exception: System.ArgumentException: Value does not  fall within the expected range.    at Microsoft.SharePoint.SPWebCollection.get_Item(Guid id)    at Microsoft.SharePoint.SPFeatureEnumeratorBase.GetCachedWeb(SPSite site, Gu id webId, Guid featureId). At line:1 char:20 + $site.QueryFeatures >> ("Web",$true)     + CategoryInfo          : InvalidOperation: (Microsoft.Share...esultCollec    tion:SPFeatureQueryResultCollection) [], RuntimeException     + FullyQualifiedErrorId : BadEnumeration

Solution

The approach to solving this issue was not to write a workaround but to run a script which checks for deleted SPWeb objects in the site collection.

1	$site = Get-SPSite http://sharepoint; $site.RecycleBin | ?{$_.ItemType -eq "Web"};

The script will display the SharePoint Web Objects that have been deleted and are still found in the site collections recycle bin.
The deleted SPWeb objects can be removed from the recycle bin using the following PowerShell command.

1	$site = Get-SPSite http://sharepoint;  $deletedWebs = $site.RecycleBin | ?{$_.ItemType -eq "Web"}; $deletedWebs | % {$site.RecycleBin.Delete($_.Id)}

This will delete the SPWeb objects from the recycle bin and the Feature Upgrade process can continue.
Please be careful when running this script! Only run it when you know that none of the SharePoint Web sites are not needed!