title: SharePoint 2010 - error reading list items "Cannot complete this action. Please try again."
body: <p>I have a SharePoint 2010 Farm solution that deploys a list, and a web part that reads from that list.  It actually does more than that, but I can't get past the "read the list" part.</p>
  
  <p>I'm able to successfully query the list and get back the SPListItemCollection, but when I attempt to loop through the items I get this totally ambiguous error "Cannot complete this action. Please try again."  Full stack trace below:</p>
  
  <pre><code>[COMException (0x80004005): Cannot complete this action.
  
  Please try again.&lt;nativehr&gt;0x80004005&lt;/nativehr&gt;&lt;nativestack&gt;&lt;/nativestack&gt;]
     Microsoft.SharePoint.Library.SPRequestInternalClass.GetListItemDataWithCallback2(IListItemSqlClient pSqlClient, String bstrUrl, String bstrListName, String bstrViewName, String bstrViewXml, SAFEARRAYFLAGS fSafeArrayFlags, ISP2DSafeArrayWriter pSACallback, ISPDataCallback pPagingCallback, ISPDataCallback pPagingPrevCallback, ISPDataCallback pFilterLinkCallback, ISPDataCallback pSchemaCallback, ISPDataCallback pRowCountCallback, Boolean&amp; pbMaximalView) +0
     Microsoft.SharePoint.Library.SPRequest.GetListItemDataWithCallback2(IListItemSqlClient pSqlClient, String bstrUrl, String bstrListName, String bstrViewName, String bstrViewXml, SAFEARRAYFLAGS fSafeArrayFlags, ISP2DSafeArrayWriter pSACallback, ISPDataCallback pPagingCallback, ISPDataCallback pPagingPrevCallback, ISPDataCallback pFilterLinkCallback, ISPDataCallback pSchemaCallback, ISPDataCallback pRowCountCallback, Boolean&amp; pbMaximalView) +256
  
  [SPException: Cannot complete this action.
  
  Please try again.]
     Microsoft.SharePoint.SPGlobal.HandleComException(COMException comEx) +27257906
     Microsoft.SharePoint.Library.SPRequest.GetListItemDataWithCallback2(IListItemSqlClient pSqlClient, String bstrUrl, String bstrListName, String bstrViewName, String bstrViewXml, SAFEARRAYFLAGS fSafeArrayFlags, ISP2DSafeArrayWriter pSACallback, ISPDataCallback pPagingCallback, ISPDataCallback pPagingPrevCallback, ISPDataCallback pFilterLinkCallback, ISPDataCallback pSchemaCallback, ISPDataCallback pRowCountCallback, Boolean&amp; pbMaximalView) +27639062
     Microsoft.SharePoint.SPListItemCollection.EnsureListItemsData() +4145
     Microsoft.SharePoint.SPListItemCollection.GetEnumerator() +146
     X.CBAS.TargetedNav.TargetedNav.TargetedNav.getUrlsForUser() +433
     X.CBAS.TargetedNav.TargetedNav.TargetedNav.CreateChildControls() +437
     System.Web.UI.Control.EnsureChildControls() +146
     X.CBAS.TargetedNav.TargetedNav.TargetedNav.OnLoad(EventArgs e) +140
     System.Web.UI.Control.LoadRecursive() +66
     System.Web.UI.Control.LoadRecursive() +191
     System.Web.UI.Control.LoadRecursive() +191
     System.Web.UI.Control.LoadRecursive() +191
     System.Web.UI.Control.LoadRecursive() +191
     System.Web.UI.Control.LoadRecursive() +191
     System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2428
  </code></pre>
  
  <p>I've looked at the list definition several times and it looks sound, as is the web part code from what I can see.  </p>
  
  <p>The list definition:</p>
  
  <pre><code>&lt;ContentTypes&gt;
    &lt;ContentTypeRef ID="0x0105"&gt;
      &lt;Folder TargetName="Link" /&gt;
    &lt;/ContentTypeRef&gt;
    &lt;ContentTypeRef ID="0x0120" /&gt;
  &lt;/ContentTypes&gt;
  &lt;Fields&gt;
    &lt;Field ID="{fa564e0f-0c70-4ab9-b863-0177e6ddd247}" Name="Title" ReadOnly="TRUE" Required="FALSE" Hidden="TRUE" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="Title"&gt;&lt;/Field&gt;
    &lt;Field ID="{82642ec8-ef9b-478f-acf9-31f7d45fbc31}" Name="LinkTitle" Hidden="TRUE" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="LinkTitle"&gt;&lt;/Field&gt;
    &lt;Field ID="{bc91a437-52e7-49e1-8c4e-4698904b2b6d}" Name="LinkTitleNoMenu" Hidden="TRUE" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="LinkTitleNoMenu"&gt;&lt;/Field&gt;
    &lt;Field ID="{081c6e4c-5c14-4f20-b23e-1a71ceb6a67c}" Name="DocIcon" DisplaceOnUpgrade="TRUE" DisplayName="$Resources:core,Type;" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="DocIcon"&gt;&lt;/Field&gt;
    &lt;Field ID="{503f1caa-358e-4918-9094-4a2cdc4bc034}" Name="Edit" DisplayName="$Resources:core,Edit;" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="Edit"&gt;&lt;/Field&gt;
    &lt;Field ID="{c29e077d-f466-4d8e-8bbe-72b66c5f205c}" Type="URL" Name="URL" DisplayName="$Resources:core,URL;" Required="TRUE" FromBaseType="TRUE" ShowInViewForms="FALSE" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="URL"&gt;&lt;/Field&gt;
    &lt;Field ID="{9da97a8a-1da5-4a77-98d3-4bc10456e700}" Type="Note" Name="Comments" DisplayName="$Resources:core,Notes;" Sortable="FALSE" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="Comments"&gt;&lt;/Field&gt;
    &lt;Field ID="{DEDA572B-9D15-4FCE-81DA-D12EE9C29D61}" Type="Text" Name="Source" DisplayName="$Resources:X.CBAS.TargetedNav,FieldSource;" StaticName="Source" /&gt;
    &lt;Field ID="{D68FEB34-BC7B-450D-8422-AA4CBA74D517}" Type="Text" Name="EpiwManagerYN" DisplayName="$Resources:X.CBAS.TargetedNav,FieldEpiwManagerYN;" StaticName="EpiwManagerYN" /&gt;
    &lt;Field ID="{2a9ab6d3-268a-4c1c-9897-e5f018f87e64}" ReadOnly="TRUE" Filterable="FALSE" Type="Computed" Name="URLwMenu" DisplayName="$Resources:core,URL;" DisplayNameSrcField="URL" ClassInfo="Menu" AuthoringInfo="$Resources:core,URLwEditMenu;" ListItemMenuAllowed="Required" LinkToItemAllowed="Prohibited" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="URLwMenu"&gt;
      &lt;FieldRefs&gt;
        &lt;FieldRef Name="URL" /&gt;
        &lt;FieldRef Name="FileLeafRef" /&gt;
        &lt;FieldRef Name="FileRef" /&gt;
        &lt;FieldRef Name="FSObjType" /&gt;
        &lt;FieldRef Name="_EditMenuTableStart2" /&gt;
        &lt;FieldRef Name="_EditMenuTableEnd" /&gt;
      &lt;/FieldRefs&gt;
    &lt;/Field&gt;
    &lt;Field ID="{7A7F3660-D408-4734-9AA0-2D86E33D79AB}" ReadOnly="TRUE" Filterable="FALSE" Type="Computed" Name="URLwMenu2" DisplayName="$Resources:core,URL;" DisplayNameSrcField="URL" ClassInfo="Menu" AuthoringInfo="$Resources:core,URLwEditMenu; (old)" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="URLwMenu2"&gt;
      &lt;FieldRefs&gt;
        &lt;FieldRef Name="URL" /&gt;
        &lt;FieldRef Name="FileLeafRef" /&gt;
        &lt;FieldRef Name="FileRef" /&gt;
        &lt;FieldRef Name="FSObjType" /&gt;
        &lt;FieldRef Name="_EditMenuTableStart" /&gt;
        &lt;FieldRef Name="_EditMenuTableEnd" /&gt;
      &lt;/FieldRefs&gt;
    &lt;/Field&gt;
    &lt;Field ID="{aeaf07ee-d2fb-448b-a7a3-cf7e062d6c2a}" DisplaceOnUpgrade="TRUE" ReadOnly="TRUE" Filterable="FALSE" Type="Computed" Name="URLNoMenu" DisplayName="$Resources:core,URL;" DisplayNameSrcField="URL" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="URLNoMenu"&gt;
      &lt;FieldRefs&gt;
        &lt;FieldRef Name="URL" /&gt;
        &lt;FieldRef Name="FileLeafRef" /&gt;
        &lt;FieldRef Name="FileRef" /&gt;
        &lt;FieldRef Name="FSObjType" /&gt;
      &lt;/FieldRefs&gt;
    &lt;/Field&gt;
  &lt;/Fields&gt;
  </code></pre>
  
  <p>The code below shows where I'm running into the error - again, nothing special:</p>
  
  <pre><code>SPQuery query = new SPQuery() { Query = this.filterQuery };
  
  //Loop through the returned URL(s) and add them to the list
  foreach (SPItem item in list.getItems(query)) { //&lt;-- Error happens here, when getting the enumerator for the SPListItemsCollection
        returnValue.Add(this.getUrlFromItem(item));
  }
  </code></pre>
  
  <p>And finally, the CAML:</p>
  
  <pre><code>&lt;Where&gt;
    &lt;FieldRef Name="Source" /&gt; 
    &lt;Value Type="Text"&gt;http://dev01:80/Pages/default.aspx&lt;/Value&gt; 
  &lt;/Where&gt;
  </code></pre>
  
  <p>Any ideas on what might be happening here would be HUGELY appreciated!</p>