Hi. . .
Open the command line (type CMD in the search box in the start/windows icon)
copy and paste this line:
regsvr32 "C:\Program Files\Autodesk\Revit Architecture 2012\Program\Revit.Thumbnail.dll"
You should get a his has been successful msg.
Restart your machine
I have try all of the solutions here and it' doesn’t work. And… I’m not only having problems with some families that doesn’t' show up on the preview window dialog box, but also, even if a family is showing the preview, ones i modified it, and save it, then it doesn’t show the preview neither, even using all of the ways suggested here to fix the problem. Please, is there any update about this issue?
I'm having this same issue and this thread does not yet have any working answer... what can I do to make file previews/thumbnails visible through windows explorer? Saving each file is not feasible because this is a problem with every single family file. I could see previews through 2013 this morning and now that 2014 has been installed all I see everywhere is the 2014 Revit logo instead of family previews. The company I work for downloaded the 2014 file directly from Autodesk so we have no CD to drag a .dll file from as other posts have suggested for earlier Revit versions. I've also checked the folders properties through windows explorer to make sure thumbnails are visible and they are. Please help.
This happens for me using the Upgrade_RFA journal script from Autodesk. I find it interesting that the only response from Autodesk is a redirect from another thread to this one, and the remaining comments keep directing people to address a Revit 2012 dll.....for a Revit 2014 thumbnail problem. I also notice that the thumbnails no longer work in the Revit file open dialog either.
I would be happy if someone could offer up how to add the "regenerate preview" to the journal script so I could test that.