Still Looking into this.
John it sounds like out set up is essentially the same R is projects but R is a different server in each offices. In the past the only issue this has caused was linking files but we could type the UNC path in the link and it was fine.
Thinking back to one of the first 2015 project we started in 2014 approx 12 months ago and then eventualy upgraded maybe 5 months ago we didn't have this issue with someone accessing it from another office. I'v egone back to that file today and had that person try to access it again and it's fine.
I've done some more tests today just making new files on my local project server (same location as that project that does work) and found the following:
![sync 2013 from 2013.jpg sync 2013 from 2013.jpg](https://forums.autodesk.com/t5/image/serverpage/image-id/159187i2BA267DA9262F775/image-size/large?v=mpbl-1&px=-1)
above: file sync path from a 2013 file still in 2013 (UNC and works fine)
![sync 2013 upgraded to 2015.jpg sync 2013 upgraded to 2015.jpg](https://forums.autodesk.com/t5/image/serverpage/image-id/159188iA03D67256D2F8DF8/image-size/large?v=mpbl-1&px=-1)
above: file sync path from detached 2013 file from above upgraded to 2015 (now uses drive letter but same location)
![2014 sync from 2014.jpg 2014 sync from 2014.jpg](https://forums.autodesk.com/t5/image/serverpage/image-id/159189iF684C22FA19115BE/image-size/large?v=mpbl-1&px=-1)
above: file sync path from 2014 file still in 2014 (UNC and works fine)
![Sync 2014 in 2015.jpg Sync 2014 in 2015.jpg](https://forums.autodesk.com/t5/image/serverpage/image-id/159190i4E96FD2713DA6034/image-size/large?v=mpbl-1&px=-1)
above: file sync path from detached 2014 file from above upgraded to 2015 (now uses drive letter but same location)
![2015 Sync.jpg 2015 Sync.jpg](https://forums.autodesk.com/t5/image/serverpage/image-id/159191i0E4088ECB479F413/image-size/large?v=mpbl-1&px=-1)
above: file sync path with new 2015 file in 2015
![sync older file in 2015.jpg sync older file in 2015.jpg](https://forums.autodesk.com/t5/image/serverpage/image-id/159192i0C05F1CA9DCA7F1E/image-size/large?v=mpbl-1&px=-1)
above: Oddly however this is the path when syncing an older file that was started in 2014 and then upgraded to 2015 but upgraded before the Revit 2015 updates where installed. (not entirely sure what updates may have been done back then.) I guess this was created in a way which utilsed the UNC path and continues to be ok.
I've tried reinstalling 2015 on a machine up to update 3 thinking that perhaps one of the latest updates has been the cause but still have the same issue with it not using the UNC path.
So there is clearly a difference in the way 2015 is generating a central file path, as seen from those tests today where all were made the same way in the same location (being my local projects folder) and you can see 2015 is not reading the UNC.
Reluctantly I will have to work on a work around to ensure central files are created through the server name etc so others from other offices can access. (one option seems to be, each time a file for Sydney needs to be made, get someone in Melbourne to make it. Then it's file path is UNC but this is not overly practical)
I would still like an explaination from Autodesk as to what has changed and why.
We're not on Revit Server either just to cross that off the list.
If I find any more discovering regarding this I'll keep you posted.
Regards
Mark