Windows Hotfix KB891781, dhtmled.ocx and the "no such interface supported" error
Or, How to fix Homesite
4.5.x Design Mode so it
Works in WindowsXP Pro SP2 and Windows Vista Business
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. 188.8.131.5231)
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.184.108.40.20627
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. 220.127.116.1127 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
(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 /u 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"
). 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.