VSOfficeDeveloper: Known Problems, Bugs, and Fixes

Problems with System.OutOfMemoryException At System.String.GetStringForStringBuilder in 32-Bit Managed Solutions

If you are working with a VSTO or managed code solution for Office, you may encounter a System.OutOfMemoryException when working with very large DataSets, XML files, or numerious object serialization calls. The problem typically occurs on a call to System.String.GetStringForStringBuilder in the managed call stack.

For details on the problem and its general cause, see the following post:
Problems with System.OutOfMemoryException At System.String.GetStringForStringBuilder in 32-Bit Managed Solutions

OLE Link to Word 97-2003 File May Fail with OLE_E_CLASSDIFF Error on Open

You may encounter an OLE_E_CLASSDIFF (0x80040008) error on calls to OleRun or IOleObject::DoVerb when attempting to bind to a Word document saved as an OLE link by Word 2007.  See the following post for details:

OLE Link to Word 97-2003 File May Fail with OLE_E_CLASSDIFF Error on Open

Unable to Open Office Documents for Edit From SharePoint Behind Cisco CSS Load Balancer

If you use a Cisco CSS switch for load balancing or content caching to a SharePoint Server farm, you may be unable to edit Office documents correctly if the switch is configured for Layer 5 content rules. By default, the Cisco CSS switch will block certain HTTP methods that are used to establish web authoring, and these can cause a problem for your Office clients and/or any SharePoint development from the client. 

Please see the following post for details:
Unable to Open Office Documents for Edit From SharePoint Behind Cisco CSS Load Balancer

Excel 2007 XLL SDK Unicode String Support Update

The Microsoft Excel 2007 XLL SDK introduced a new data structure, the XLOPER12, which allows your addin to obtain Unicode strings in XLL function calls.  However, there were a couple of limitations with the implemention of the SDK which prevented your XLL from taking full advantage of this new capability. Specifically, while Excel 12 would allow strings in Unicode, some functions would still insist on a 255 character limit if the resulting XLL type was an XLOPER12 type (instead of a LPWSTR type), restricting the length of the overall string.  Also, the benefits of the new string type did not carry over to setting strings with the xlSet function, only accepting them as parameters or reading them as results from certain callback functions.

Excel development has addressed these limitations in a comprehensive fix for Excel 2007, released as part of the the August 2008 Cumulative Update for Excel 2007 (see KB956836 ).

Problems with SharePoint DateTime Columns in Office 2007 Documents Edited by Office 2003

A problem was recently discovered with the Office 2007 Compatibility Pack file converters when used to open Office 2007 Open XML files in previous Office versions, when those files have custom Date/Time properties attached associated with SharePoint. If the documents are opened and saved back to SharePoint in Office XP/2003, the Date/Time property may accidently get modified to an incorrect time due to a bug in UTC-to-Local time conversion.

See the following post for full details:
SharePoint Document Library Date Time Columns May Be Incorrectly Changed for Office 2007 Documents if Opened and Saved by Office XP/2003

Field’s promoted from an InfoPath form template during publishing to a Microsoft Office SharePoint Server are created multiple times

When publishing an InfoPath Form Template (XSN file) to multiple servers (i.e. a development server and a production server) and you are promoting fields from the InfoPath data source to be created as columns in SharePoint, those fields may get recreated each time you publish the XSN.

See the following post for more information:
Field’s promoted from an InfoPath form template during publishing to a Microsoft Office SharePoint Server are created multiple times

Office 2007 File Format MIME Types for HTTP Content Streaming

The following post offers documentation on the Office 2007 MIME Types that can be used for HTTP content streaming to Office 2007 applications. Due to security measures in both IE and Office 2007, it is important that web sites return Office 2007 content with the correct MIME type header for the type of content returned during a hyperlink navigation.  To see a list of the types and the extensions they map to, see this article post:

Office 2007 File Format MIME Types for HTTP Content Streaming

Visio cannot Open read-only documents from a Document Management System

For full details, see the following post:

Visio cannot Open read-only documents from a Document Management System

OCX Controls Used in VBA-Enabled Applications Cannot be Side-By-Side (SxS) Registered

ActiveX Controls used in Office applications with VBA must have at least their type library registered in the registry to work properly.  VBA does not support Side-By-Side (SxS) registration of controls and this may prevent a control registered only by SxS from working correctly in Office.

See the following post for more details:
OCX Controls Used in VBA-Enabled Applications Cannot be Side-By-Side (SxS) Registered

ShellExecute fails when called from Internet Explorer Protected Mode

When calling ShellExecute to open an Office document from Internet Explorer, the call will fail with a “File not Found” error if Protected Mode is turned on. The problem occurs after installing Office 2007 Service Pack 1 on Windows Vista.

For full details, see the following post:

ShellExecute fails when called from Internet Explorer Protected Mode

OLE/ActiveX Objects Copied from Office in Remote TS Session are Unavailable on Local Client Via RDP Clipboard

When attempting to copy and paste OLE or OCX objects from Office applications running on a remote desktop to another application running on your local desktop, you may fail to get the data expected, or will find the data is unavailable from the Paste Special dialog. 

For full details, see the following post:
OLE/ActiveX Objects Copied from Office in Remote TS Session are Unavailable on Local Client Via RDP Clipboard

Excel OLE Embedding Errors if you have Managed Add-In Sinking Application Events in Excel

Managed addins/components that sink events on the Application object may cause problems with OLE functionality in that instance of Excel, resulting in errors or possible crash of host application trying to edit Excel embedded objects.  Managed addins can avoid this problem with custom code. Users seeing this problem can avoid the problems using an Excel instance that does not load the managed addin.

For details about this problem and what developers building managed addins can do to avoid it, see this post:
Excel OLE Embedding Errors if you have Managed Add-In Sinking Application Events in Excel

Excel 2007 does not return shape data using XLL xlfGetDocument command

XLL add-ins using the xlfGetDocument command to obtain shape data may fail in Excel 2007 because a known problem in that version. The bug is being investigated for a fix in a future Excel release.

See the following post for more details:

Excel 2007 does not return shape data using XLL xlfGetDocument command

Changes in OCX Save Behavior for Office 2007 Documents

Office 2007 introduces a new save behavior for ActiveX Controls (OCX) saved directly in Word, Excel, and PowerPoint documents.  As part of the new Open XML file format, OCX controls can be persisted as XML data if the control supports saving by IPersistPropertyBag using data types easily converted to text formats.  This new behavior offers greater compatibility with the Open XML file format, but can cause backward compatibility problems for certain controls that only know how to save in binary fashion. 

Click the link below to read about this issue and what you (as an OCX developer) should consider when implementing IPersistPropertyBag:

Changes in OCX Save Behavior for Office 2007 Documents

Description of the Microsoft Office Existence Discovery Protocol

Microsoft Office 2007 applications can make an HTTP HEAD request to the URL location where a document is open from.  This request is new to Office 2007, and goes by the name "Microsoft Office Existence Discovery Protocol".  The following posting describes this protocol and its intended use.

To read the full posting for this issue, see this site:
Description of the Microsoft Office Existence Discovery Protocol