In an environment with Site-to-Site VPNs and Windows 7 clients on the branch offices you can be faced with the Error 0x80070035 – The network path was not found, when users try to access file services provided with DFS shares.
The standard protocol used to access file services is SMBv1 and SMBv2, depending on legacy client and servers or current version OS client and server like Windows 7 and Windows Server 2008 R2.
There is a bug in the Mrsxsmb10.drv driver, causing some trouble.
Read the MSKB article
and apply the hotfix to fix the problem.