Unable to open document library in explorer view

While working for some client, I came across this issue with a document library which has more than 20000 documents in it. It was working before but suddenly one day user reported the error shown below while opening document library in windows explorer view –

\\sitecollection\DavWWWRoot\subsite\documentlibrary is not accessible. You might not have permissions to use this network resource. Contact the administrator of this server to find out if you have access permissions.

A device attached to the system is not functioning.

 

CAUSE –

Sadly this problem doesn’t have anything to do with permissions or devices that are not attached or not functioning so the message is misleading. The message is probably used for a variety of issues.  When the number of items in the document library exceeds the number specified in the registry it will throw the error and you will not be able to access the explorer view.

This problem may occur if all the following conditions are true:
  • The client computer is running one of the following configurations:
    • Windows XP with Service Pack 1 (SP1) and security update 896426
    • Windows XP with Service Pack 2 (SP2)
    • Windows XP Professional x64 Edition
    • Windows 7
    • Windows 8
    • Windows 8.1
  • The WebDAV folder contains many files. For example,  the folder contains 20,000 or more files.  By default, Windows XP will enumerate approximately 1,000 files in one Web folder. This number is based on the default setting for the following registry subkey:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WebClient\Parameters\

    Value: FileAttributesLimitInBytes Data Type: DWORD Default Value: 1,000,000 decimal (1 MB) Description: This registry subkey determines the maximum collective size of all file attributes in one folder that is allowed by the WebDAV redirector. This attribute limit covers all the PROPFIND and PROPPATCH responses.

The problem occurs because the size of all the file attributes  that are returned by the WebDAV server is much larger than what is expected. By default, this size is limited to 1 MB. This limit is for security reasons.

WORKAROUND –

The workaround to this problem is a two step process – first, you need to Configure the FileAttributesLimitInBytes registry value to the size that you want and then restart the ‘WebClient’ service.

To do this, follow these steps:

  1. Click Start, click Run, type regedit, and then click OK.
  2. Locate and then click the following registry subkey:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WebClient\Parameters\
  3. Right-click FileAttributesLimitInBytes, and then click Modify.
  4. In the Value data box, type the value that you want to use, and then click OK. For example, if the Web folder contains 20,000 files, type 20000000 in the Value data box.
    Note If the default value is 1,000,000 (1 MB), Windows will enumerate a maximum of approximately 1,000 files in one folder. The actual maximum number of files may vary, depending on the number of file attributes or file properties. By default, the WebClient service does not ask for specific WebDAV properties. Therefore, the server returns all file attributes. The Microsoft Office-integrated Webfolders redirector does ask for specific WebDAV properties.
  5. Exit Registry Editor.
  6. Stop and then restart the WebClient service. To do this, follow these steps:
    1. Click Start, click Run, type cmd, and then click OK.
    2. Type the following commands, and then press ENTER after each command:
      net stop webclient net start webclient

Trackbacks

Leave a Comment

Your email address will not be published. Required fields are marked *