I am sorry for the inconvenience caused to you.
Could you please check and confirm the version of Lightroom you are using?
Also, please provide us the workflow and error message if any.
Please refer to the below link and see if this helps.
The link you've provided outlines what appears to be the same issue, though I'm unclear what the fix is beyond buying a new version of Lightroom, though I might have missed something. Also, most of the troubleshooting seems to be for Photoshop, not Topaz, and - not being a computer whiz - am unsure if the steps are relevant or not.
I'm currently using Lightroom 4 and when I open Photo>Edit In, nothing happens. I've uninstalled and reinstalled Lightroom, as well as Topaz and its various products. And as mentioned, the Topaz support team has spent two weeks trouble shooting, including confirming the 'preference settings' are correct and that the permissions in 'Terminal' are right. Thus, after all of their tests, they discovered a flaw in Lightroom, though without a specific error message.
Can you, as simply as possible, spell out what steps I need to take to fix the bug so I can get my images through my workflow before my book project deadline at the end of the month?
Unless something has changed in how Topaz does things, you need Fusion Express between Lr and Topaz plugins: the plugins aren't standalone editors that Lr can send an image to - you need the interface that Fusion Express provides.
It'd also help to know which Topaz products you're trying to access - there are umpteen of the things, some of which are stand-alone.
Sorry, I should have mentioned that I have Fusion Express 2 installed and have confirmed there isn't an issue with its abilities. I have the full Topaz suite. None of the programs work.
Basically, when I select Photo>Edit In within Lightroom, nothing happens, no matter what program I select.
And you've definitely added Fusion Express as an external editor in the Preferences? (I know you've said that your Preferences settings are right, but - just for completeness - you've done this? http://asseenbyjanineblog.com/wp-content/uploads/2012/06/3-Additional-External-Editor-Sele ct-Fusion-Express-2.jpg)
Yes, and that's been doubled verified by Topaz.