This PCSTATS Tech Tip is a very specific solution to a general problem encountered by web developers who use certain HTML editors. When Microsoft released the infamous KB891781 hotfix for WindowsXP SP2 in '05, it disabled a crucial Dynamic HTML Editing Control that many applications rely on to function. Most notably, HomeSite 4.5.x began spitting up "no such interface supported" errors and crashing instantly when code was brought into the internal 'Design' view.

The hotfix apparently broke equivalent aspects in WebsiteWeaver, CoffeeCup, KLZ NewsRoom4 and CityDesk among other applications. 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 WinXP 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 MSFT messed up. :-)

HomeSite 4.5.2 was released when Allaire was still in business, the current HomeSite 5.5 version is an Adobe product. As HomeSite 4.5.x was the last iteration to retain the Design mode feature, this old version is still widely used. 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. PCSTATS swears by it for quickly formatting our articles, this newsletter and text heavy content for the web.

The problem today is migrating from WindowsXP Professional to Windows Vista Business - a natural progression many web developers are facing - and taking this legacy programming app. along for the ride. Vista software compatibility is a mixed bag at best, and in general it's always wise to run pre-Vista software in the appropriate Compatibility Mode with Administrator Privilege Levels set. 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 this time, but luckily the fix isn't too troublesome to apply.

In WindowsXP SP2 systems the root of the problem was 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 didn't work. 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, then "regsvr32.exe " to re-register it along with one other file back into the registry.

The steps outlined below can apply to either WindowsXP Professional SP2 or Windows Vista Business. First 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, 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 if everything works 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.

The Vista Specific Solution

In researching this Tech Tip, PCSTATS also came across this Vista specific downloadable patch from Microsoft for "DHTML Editing Control for Applications" ( http://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.

Send your comments, suggestions, errors, warnings, and feedback on this tip here.