So I found a solution, using KB and other sources. Here it is:
1. PS just a note: eDrawings preview of DXF files fail when "Show bitmaps for SolidWorks files" is enabled - if you want to use preview of dxf files with eDrawings - disable bitmap preview for Solidworks files
So for the TrueView:
2. DWG TrueView 2015 no longer work in Preview tab since Active-X control 'acctrl.dll' has changed to 'dwgviewrAcCtrl.dll' *Regression* If DWG TrueView 2014 or older is installed, and registered (see attached 'How to register the DWG TrueView Active-X control.pdf'), previwing a DWG file should use the TrueView Active-x instead of eDrawings. However, this no longer works when installing TrueView 2015 - likely because they have changed the name of the TrueView Active-X control to 'dwgviewrAcCtrl.dll' instead of the 'acctrl.dll' as it was called in TrueView 2014 and older.
SO: download and install true view 2014 (do not use 2015 version)
3. Register required library:
A - run CMD (As administrator)
B - Step into the DWG TrueView install folder and type the following to register the TrueView active-x
C - Restart the system.
D - To verify that the active-X control registered, start the registry editor (start, run, regedit) and locate the
following registry key:
The key should show the path to the acctrl.dll file and a “ThreadingModel” string containing value
“Apartment” . If either or both values are missing, try registering the DLL again.
If it still fails to create the key, reinstall TrueView and reregister the dll.
4. Makes sure registry values for DWG and DXF are correct for ePDM:
HKEY LOCAL MACHINE > Software > Solidworks > PDMWorks Enterprice > FileFormats
check folders .dwg and .dxf - ensure they contain these values:
If they are not there - create them and restart explorer or full PC