Bulk Deletion of Events from a SharePoint Calendar

Assume you have a SharePoint Calendar with thousands of events, including recurring events, and recurring event exceptions. These ones are the result of aggregating events from several years, most of them are no more relevant.

Problems

If the number of events is over the List View Threshold limit, your users will not be able to access the All Events view (see sample screenshot below taken from another calendar including a standard and a recurring event, a deleted recurring event and a recurrence exception),

they receive instead that an error message:

The attempted operation is prohibited because it exceeds the list view threshold enforced by the administrator.

They won’t be able even to delete the calendar, either from the Site Content page (they get a warning like “We’re sorry, we had some trouble removing this. You can try again from the settings page.”):

or from the Settings page of the list (same error as above):

Of course, you as an administrator, can increase the List View Threshold limit, delete the list via PowerShell (see below), or even from the web UI if you log in using the farm account, but it takes more time for you and for your users.

$web = Get-SPWeb http://YourSharePoint/Web/SubWeb
$calendar= $web.lists["YourCalendar"]
$calendar.Delete()

Even if the number of events stays below the List View Threshold limit, the users might have experience performance problems.

Solution

Note, that we did not want to delete the list, the limitation with the deletion was only one of the examples. Instead of deletion, we wanted to drastically reduce the number of events by deleting all events that are no more relevant in the current year. That means, deleting all single events that were finished earlier than this year, and repeating events whose repetitions is finished earlier than the current year.

Based on my experience the deletion of such high number of items is not very performant, so I decided to delete the items in batches. There are several examples for that on the web, including solutions for C# (see here or here) or for PowerShell (see here) or for both of them (see this one). I planned to use PowerShell, but the examples I found were typically simple translations of the C# version, without using the structures and features available in PowerShell. Even worse, both the C# and PowerShell implementations out there have a serious limitation: they either output all of the results returned by the ProcessBatchData method, or they display no information at all. It might be OK as long as you successfully delete all of the items, but if you have any problem there, I wish you a good luck to find any usable information about it, if there are really of thousands of items in your list. So I created my own PowerShell implementation using the samples available. Note, that because I don’t want to wait for a feedback about the success of the deletion until all items are processed (we had over some 10k items there), I’m deleting the items in smaller batches, in the code below it is 1000 items / batch.

To get the items I should delete, I used the following CAML query:

<Where>
    <Lt>
    <FieldRef Name=’EndDate’ />
    <Value Type=’DateTime’>2017-01-01 00:00:00</Value>
    </Lt>
</Where>

Here is the full code of the first version of my script, see how I process the results by splitting the response XML to successfully deleted items an failures, and displaying only the latter ones:

Although a few events have been really deleted, I started to get the following errors very quickly, and no deletion was performed after that:

The error messages above correspond to the following XML response:

<Result ID="" Code="-2147023673">
<ErrorText>The operation failed because an unexpected error occurred. (Result Code: 0x800704c7)</ErrorText></Result>

In the ULS logs I found a lot of such entries:

Batchmgr Method error. Errorcode: 0x1c32cbb0. Error message: The operation failed because an unexpected error occurred. (Result Code: 0x800704c7)

and at the top of the a single entry like this:

Batchmgr Method error. Errorcode: 0x1c32cbb0. Error message: Item does not exist.  The page you selected contains an item that does not exist.  It may have been deleted by another user.

After that, I’ve tried to delete the items using the same CAML query, hoping that I get more information about the failure. I used this script:

I’ve got similar error messages as earlier for specific items, but the deletion went further than:

Exception calling "Delete" with "0" argument(s): "Item does not exist.
The page you selected contains an item that does not exist.  It may have been
deleted by another user."
At line:19 char:3
+   $item.Delete()
+   ~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException 
    + FullyQualifiedErrorId : SPException

I stopped the script after a while, and checked the ULS logs:

Item does not exist.  The page you selected contains an item that does not exist.  It may have been deleted by another user.<nativehr>0x81020016</nativehr><nativestack></nativestack>
SPRequest.GetListItemDataWithCallback2: UserPrincipalName=i:0).w|s-1-5-21-3634847118-1559816030-2180994487-3194, AppPrincipalName= ,pSqlClient=<null> ,bstrUrl=http://YourSharePoint/Web/SubWeb ,bstrListName={2A67D5C3-7AC1-4F3E-AB47-2051CDB94237} ,bstrViewName=<null> ,bstrViewXml=<View Scope="RecursiveAll" ModerationType="Moderator"><Query><Where><Eq><FieldRef Name="ID"></FieldRef><Value Type="Integer">2328</Value></Eq></Where></Query><RowLimit Paged="TRUE">1</RowLimit></View> ,fSafeArrayFlags=SAFEARRAYFLAG_NONE
System.Runtime.InteropServices.COMException: Item does not exist.  The page you selected contains an item that does not exist.  It may have been deleted by another user.<nativehr>0x81020016</nativehr><nativestack></nativestack>, StackTrace:    at Microsoft.SharePoint.SPListItemCollection.EnsureListItemsData()     at Microsoft.SharePoint.SPListItemCollection.get_Count()     at Microsoft.SharePoint.SPList.GetItemById(String strId, Int32 id, String strRootFolder, Boolean cacheRowsetAndId, String strViewFields, Boolean bDatesInUtc, Boolean bExpandQuery)     at Microsoft.SharePoint.SPList.GetItemById(String strId, Int32 id, String strRootFolder, Boolean cacheRowsetAndId, String strViewFields, Boolean bDatesInUtc)     at Microsoft.SharePoint.SPList.GetItemById(String strId, Int32 id, String strR…
…ment.Automation.Runspaces.RunspaceBase.RunActionIfNoRunningPipelinesWithThreadCheck(Action action)     at System.Management.Automation.ScriptBlock.InvokeWithPipe(Boolean useLocalScope, ErrorHandlingBehavior errorHandlingBehavior, Object dollarUnder, Object input, Object scriptThis, Pipe outputPipe, InvocationInfo invocationInfo, Object[] args)     at System.Management.Automation.ScriptBlock.InvokeUsingCmdlet(Cmdlet contextCmdlet, Boolean useLocalScope, ErrorHandlingBehavior errorHandlingBehavior, Object dollarUnder, Object input, Object scriptThis, Object[] args)     at Microsoft.PowerShell.Commands.ForEachObjectCommand.ProcessRecord()     at System.Management.Automation.CommandProcessor.ProcessRecord()     at System.Management.Automation.CommandProcessorBase.DoExecute()     at System.Mana…
Item does not exist.  The page you selected contains an item that does not exist.  It may have been deleted by another user.<nativehr>0x81020016</nativehr><nativestack></nativestack>
SPRequest.DeleteItem: UserPrincipalName=i:0).w|s-1-5-21-3634847118-1559816030-2180994487-3194, AppPrincipalName= ,bstrUrl=http://YourSharePoint/Web/SubWeb ,bstrListName={2A67D5C3-7AC1-4F3E-AB47-2051CDB94237} ,lID=2327 ,dwDeleteOp=3 ,bUnRestrictedUpdateInProgress=False
System.Runtime.InteropServices.COMException: Item does not exist.  The page you selected contains an item that does not exist.  It may have been deleted by another user.<nativehr>0x81020016</nativehr><nativestack></nativestack>, StackTrace:    at Microsoft.SharePoint.SPListItem.DeleteCore(DeleteOp deleteOp)     at Microsoft.SharePoint.SPListItem.Delete()     at CallSite.Target(Closure , CallSite , Object )     at <ScriptBlock>(Closure , FunctionContext )     at System.Management.Automation.Interpreter.LightLambda.RunVoid1[T0](T0 arg0)     at System.Management.Automation.ScriptBlock.InvokeWithPipeImpl(Boolean createLocalScope, ErrorHandlingBehavior errorHandlingBehavior, Object dollarUnder, Object input, Object scriptThis, Pipe outputPipe, InvocationInfo invocationInfo, Object[] args)     a…

What should it mean, that specific items were deleted? I was sure, I work alone on the calendar. Fortunately, I already worked a lot previously with calendar entries, so it took not very long time to find a reason for the problem.

You should know, that if you delete the “master” item of the recurring events in SharePoint (and we had a lot of them in this case), all of the series exception are deleted the same time. As our original query returned this exception items as well, we had errors when we wanted to delete the already deleted items. The second script (without batch deletion) was able to survive it, but the batch deletion script got mad because of that.

What’s the solution for this issue? Let’s fix our CAML query and select only the items that are not recurring event exceptions:

<Where>
    <And>
    <Lt>
        <FieldRef Name=’EndDate’ />
        <Value Type=’DateTime’>2017-01-01 00:00:00</Value>
    </Lt>
    <Lt>
        <FieldRef Name=’EventType’/>
        <Value Type=’Integer’>2</Value>
    </Lt>
    </And>
</Where>

The query for EventType less than 2 originates from my practice, an unofficial documentation can be found here. The event types are defined (at least more or less) in the internal static class Microsoft.SharePoint.ApplicationPages.Calendar.EventType, for example Deleted has a value 3 and Updated has a value of 4.

The updated script:

Using the modified CAML query I had no more errors, BUT according to the comment of Andrey Markeev in this thread, batch deleting only moves the items to the Recycle Bin, instead of really deleting them. That is not optimal for me.

To delete the items from the Recycle Bin as well, there are two main alternative solutions. Either you extend the batch deletion script with removing recycled items from the Recycle Bin, or you perform a cleanup in a second step.

The code samples in the forum thread referred to earlier as well are deleting either all items from the Recycle Bin, or trying to delete the items using the original list item ID, although the ID in the Recycle Bin differs from the original one. That is either not ideal or does not function. If you invoke the Recycle method of a SPListItem instance, the new ID, the transaction ID is returned to you (as a Guid), but this information is unfortunately not available by batch deletion. We had no folder structure in our calendar, so the LeafName property of the SPRecycleBinItem correspond to the server relative URL of the root folder of the source list (where the item was deleted) without the leading slash, and the DirName property corresponds to the list item ID (ending with ‘_.000’), so we can simply make a query for the IDs in the Recycle Bin, and remove them permanently:

$recBin = $web.Site.RecycleBin
$recBinIds = @($recBin | ? { $itemIds -contains $_.LeafName.Trim(‘_.000’) -and $_.DirName -eq $list.RootFolder.ServerRelativeUrl.Trim(‘/’) } | % { $_.ID })
$recBin.Delete($recBinIds)

Note, that this script is not universal. It might not function, if you have deleted an item from a list including folder structure or a document from a library. For example, in the case of a document library the LeafName property correspond to the file name without the extension and not to the ID.

The updated script:

As the second option, you can delete all items you recycled from the calendar after you have finished the batch deletion. The script below removes items from the Recycle Bin that were deleted from the calendar in the past hour by the current user:

$recBin = $web.Site.RecycleBin
$ids = $recBin | ? { $_.DeletedDate -gt (Get-Date).ToUniversalTime().AddHours(-1) -and $_.DirName -eq ‘Web/SubWeb/Lists/YourCalendar’ -and $_.DeletedById -eq $web.CurrentUser.ID } | % { $_.ID }
Write-Host Deleting $ids.Count item from recycle bin…
$recBin.Delete($ids)

If the deletion was quicker than 60 minutes, you can reduce the time span used in the script, to reduce the possibility you delete an item inadvertently from the Recycle Bin.