Managing Windows file name length in DAS

Windows has a file name length limit of 260 characters and a folder name length limit of 248 characters. There are two areas where this could potentially impact Nutrient Document Automation Server (DAS) — previously known as Document Automation Server (DAS) — processing.

File name length — UNC paths

If a local file path is at or close to one of the Windows limits, it can potentially cause issues — for example, if the file path is equal to or more than 260 characters:

C:\documents\major accounts payable 2010\\......with 260 characters.pdf

When the file above is accessed remotely via a universal naming convention (UNC), as shown below, it’ll exceed the 260 character Windows file name limit during Nutrient DAS processing. This can even affect files that are to be filtered out — for example, .msg files in the case where .pdf has been specified as a filter.

\servername\c$:\documents\major accounts payable 2010\.......with 260 characters.pdf

The best solution for this problem is to create a share so that the UNC path won’t exceed the limit.

For example, create a share to C:\documents\major accounts payable 2010 with a short name such as dp2. This will allow access via a UNC such as \\servername\dp2\.......with 260 characters.pdf.

In other words, in Designer, the source folder is \\servername\dp2 rather than \\servername\c$:\documents\major accounts payable 2010.

File name length — Nutrient DAS working folder paths

For integrity reasons, Nutrient DAS will, by default, copy source files and write processed files to work folders before copying to the target output folders. The location of work folders is defined in the job manager — for example, C:\Aquaforest\Autobahn DX\work\1008.

As an example, given a file named C:\Accounts\Business Documents 2010\Invoices\......with 260 characters.pdf and the source folder defined as C:\Accounts\Business Documents 2010\Invoices, the work folder will be C:\Aquaforest\Autobahn DX\work\1008\ Invoices\....with 260 characters.pdf, which will exceed the limit.

The best solution is to shorten the work folder path via the Designer screen — for example, to C:\dw\1008 instead of C:\Aquaforest\Autobahn DX\work\1008.

Long file name support

Starting in Windows 10 and Windows Server 2016, version 1607, MAX_PATH limitations have been removed from common Win32 file and directory functions. However, you must opt in to the new behavior. This section will show you how to configure your computer and Nutrient DAS to use long file names.

Nutrient DAS configuration

  • Open the Nutrient DAS configuration file found in the location below:

    • “Autobahn Install Folder\ config\Autobahn.config”

  • Set the “allowlongfilename” value to “True”, as shown below:

    • <add key="allowlongfilename" value="True" />

Windows configuration

  • Start the registry editor (regedit.exe).

  • Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem.

  • Double-click LongPathsEnabled.

  • Set its Value data to 1 and click OK.

  • Reboot.