So why does Homesite Design mode no longer work? Well it all goes back to a day in 2005 when Microsoft released the infamous KB891781 hotfix for WindowsXP SP2. This hotfix disabled a crucial Dynamic HTML Editing Control in the operating system that many applications relied on to function. Most notably, HomeSite 4.5.x began spitting up "no such interface supported" errors and crashing instantly when HTML code was brought into the programs internal 'Design' view pane. The KB891781 hotfix apparently broke equivalent aspects in programs like Website Weaver, CoffeeCup, KLZ NewsRoom4 and CityDesk among other applications.

Microsoft: Protecting you by breaking your software

Microsoft released the KB891781 critical update to prevent malicious websites from accessing a PC though Internet Explorer, and since its release the only real work around for the havoc it wrought has been to uninstall the hotfix. Hardly an ideal solution for Windows XP users, and completely ineffective within Windows Vista.

As it happens, a little known fix for the WindowsXP KB891781 hotfix can also be applied to Windows Vista Business - and this is why PCSTATS is talking about a 2 year old patch job Microsoft messed up. :-)

The Legacy Software Transition - From Windows XP to Vista

HomeSite 4.5.2 was released by a software company called Allaire. That company was bought by Macromedia, which was later acquired by the makers of Photoshop, and thus today the current HomeSite 5.5 version is an Adobe product. As HomeSite 4.5.x was the last iteration to retain its Design mode feature, this old version is still widely used by developers. Now, no web programmer worth their salt would ever use a WYSIWYG editor for coding up a website, but for the convenience of laying down content with images and charts, Homesite's Design mode is still an invaluable tool. For doing article layouts, PCSTATS swears by it. The design mode allows us to quickly format our articles, the PCSTATS newsletter and any text heavy content for the web with a minimum of fuss.

The problem today is migrating from WindowsXP Professional to Windows Vista Business - a natural progression many web developers are embarking on.

As you transition from WindowsXP to a new operating system, it's not unreasonable to assume you want to take your legacy programming applications along for the ride. The situation isn't helped much by the fact that Microsoft Vista software compatibility is a mixed bag at best. In general it's always wise to run pre-Vista software in the appropriate Vista Compatibility Mode, with Administrator Privilege Levels set.

To do that, right click on the application shortcut > Properties > hit the Compatibility tab and you'll find the necessary options. The Compatibility tab won't help us get the Design mode in Homesite working, but luckily the fix isn't too troublesome to apply.

Fixing Homesite Design Mode

In WindowsXP Service Pack 2 (SP2) systems, the root of the problem is that hotfix KB891781 installed an updated dhtmled.ocx (ver. 6.1.0.9231) file in the 'C:\Program Files\Common Files\microsoft shared\Triedit' directory. That updated filed is broken, and doesn't work like the previous version did.

The fix for WindowsXP SP2 (and Vista Business) systems is to replace that file with an earlier version, the v.6.1.0.9227 dhtmled.ocx file that existed pre-KB891791 patch. You can determine a file version by right clicking on the application file > Properties > Version or Details. After replacing the non-functioning dhtmled.ocx with the earlier version, the command "regsvr32.exe /u" is used to unload it from the system registry, then "regsvr32.exe" is used to re-register it along with one other file back into the registry.

The steps outlined below apply to a computer system installed with either a WindowsXP Professional SP2 or Windows Vista Business.

Close Homesite if you have it running. Then, backup your PCs original "dhtmled.ocx" file by renaming it to "dhtmled.ocx_old". For your convenience, ver. 6.1.0.9227 of dhtmled.ocx can be downloaded here. Download and save it to C:\Program Files\Common Files\microsoft shared\Triedit. Go to Start > Run > type "cmd" >at the prompt type "cd C:\Program Files\Common Files\microsoft shared\Triedit" (without the quotes).

Next, enter each of the following commands in sequence, hitting "enter" after each line and click 'okay' in the window that pops up to say command successfully completed:

regsvr32.exe /u dhtmled.ocx
regsvr32.exe dhtmled.ocx
regsvr32.exe /u triedit.dll
regsvr32.exe triedit.dll

Restart Homesite 4.5.x (or your affected application) and test the Design mode with an html file - open it, do some changes, switch back to 'Edit' and see if everything works. If it does the "No Such Interface Supported" error is a thing of the past!

Again, we've found this fix to work in both WindowsXP Professional SP2 and Windows Vista Business.

Windows Vista and Windows 7 Specific Solutions

In researching this short but handy Guide, PCSTATS also came across this Windows Vista/7 specific downloadable patch from Microsoft for "DHTML Editing Control for Applications" ( https://www.microsoft.com/downloads/details.aspx?familyid=b769a4b8-48ed-41a1-8095-5a086d1937cb&displaylang=en ). it essentially does what we've just described, installing the two files noted above to 'C:\Program Files\Common Files\microsoft shared\DhtmlEd' and registering them with the system... in one swift click. Alas.