3D models disappeared from camera view (or indeed stage view)

I have an issue here with TB STB 4.1.
I reopened my file and can see the 3D models in the thumbnails but cannot see them in my camera view. Reopened , opened a back-up file , rebooted the PC , checked graphic card driver etc. To no avail.
Tried to replace the 3D objects listed in my library but then I loose the views in the thumbnail images too.

Seems like TB STB somehow lost a link to it’s library where the 3D obj files should be stored.
Can find the library where 2D files (jpegs with designs and such) are stored but can’t find the location for the obj files. Should be somewhere in …Toon Boom Storyboard Pro 4.1 / win64 / bin file ?

Windows 7 pro 64
Nvidia quadro K2000

create a new project and import a new obj. in the library.
Dragit into a scene. No problem there.
Save and immediately reopen: all gone.

Obviously not a ‘renamed files or folders’ issue.

Am on a deadline and need to solve this. Any ideas anyone?

Can anybody tell me what would happen if I re-installed the soft? What with the library. Now I can see that my project has still stored the data for the 3D objects. All that’s missing I think is a link to the right .obj file .
I have V 2.0 installed on the same PC. Could that be the issue here?

Urgent!

Can anybody tell me what would happen if I re-installed the soft? What with the library. Now I can see that my project has still stored the data for the 3D objects. All that’s missing I think is a link to the right .obj file .
I have V 2.0 installed on the same PC. Could that be the issue here?

Urgent!

I noticed that the soft on importing an .obj file created a new truncated name for the obj file in the library alongside the full name of the file. So I thought maybe the name of the .obj file is simply too long and indeed when I created a new project imported a renamed (shorter name) .obj file everything seemed to work fine.

Question remains of how can I restore my project. Tried renaming the .obj in the project file (Elements>ObjModels). Giving it the same truncated name the soft created.To no avail.
As said the soft seems to have kept all the data re. location , position , size and so on but seems not to be able to find the right .obj.

How can I restore the link?

I am having a similar issue where the 3D models in my scene disappear. When I scrub the timeline or play the animatic the models reappear. On playback though, the camera mask disappears. At any rate its hard to draw if I cant reference the models or get an accurate playback.

Any ideas on why this is happening?