Hello, 

I'll start off by describing the environment:

• I have a virtual Windows 2008 R2 File Server with current patches with a shared folder (E:\Data). 
• I have a Windows 7 Enterprise N x64 Client also with current patches, and Office 2013 x86, also patched. The Client has a share from the Server mapped as (N:\) 
• The User has Full Control in the NTFS Permissions and in the Share Permissions as well. 

Since about 3 weeks, we have been having the odd behavior that when I try to copy files to the mapped drive I get the error that the file path is too long, or the file extension is invalid. It becomes even more odd, when I try to do the same thing, except using the UNC Path it works. When I try to do it using xcopy, it works. When I map the folder as a network location it works.

It only does this when I try to replace a file that already exists.

Another problem I have which probably is related is, when I try to attach a file from said mapped drive to an email, I get the message that the file path couldn't be found.

Please let me know if anyone else has this problem, and how to fix it

Kind Regards,

JS

Hi,

Based on the error message >>get the error that the file path is too long, or the file extension is invalid<<, and the maximum length for UNC, which is defined as 260 characters. Please check your length of UNC path first.

Reference:

https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396#maxpath

Hope it's helpful.

Regards,

George Zhao
TechNet Community Support

Hi,

The unc path is definitely not longer than 260 chars. See below. And if it was longer, it wouldn't work all together, but it does, just not when the client has it mapped as a network drive. 

UNC: \\swb-file\Daten\Sicherheitsdatenblaetter\tectyl.pdf 

Local on the server: 

E:\Daten\Sicherheitsdatenblaetter\tectyl.pdf

Regards,

JS