Issue
When trying to open a DWF image or when trying to add DWF files to a project or access a DWF image in an existing project, this error message displays:
"DWF support is not currently installed. Would you like to download and install it now?"
Discussion
Previous versions of On-Screen Takeoff worked with AutoDesk's "Design Review 2008", however that program no longer works on Windows.
Use of DWF files has fallen off significantly, so we decided to no longer support using DWF files natively in On-Screen Takeoff.
Resolution
To view DWF files in On-Screen Takeoff, you must convert them to PDF or TIF (outside of On-Screen Takeoff).
There are several CAD image converters available, AutoDesk provides a free, online DWF viewer at https://viewer.autodesk.com/ .
You must register for a free account with AutoDesk to use the online DWF Viewer.
From there, you can upload your DWF file, and then PRINT each (at high resolution, full-size) to a PDF, and then use those PDFs in On-Screen Takeoff.