Had an interesting case where Biztalk File Receieve locations were becoming disabled.  Most commonly this is caused by an issues with maxcmds which is documented here:  http://support.microsoft.com/kb/810886  In some cases this is is due to the following issues.  http://support.microsoft.com/kb/943859

 

The eventlog entry for the event looked like this:

9/30/2008    2:40:50 PM    BizTalk Server 2006    Error    BizTalk Server 2006     7176    N/A    BTSERVER The FILE receive location \\Server\Share is invalid. Error occurred when reading this receive location.

In this case it turned out to be due to some errors that were occurring at the network level.  In order to determine if your environment is seeing this particular problem, take a network capture using Netmon 3.1.

Apply a Display filter.

smb.DOSError.Error != 0 || smb.NTStatus.Code != 0

You will see errors that look like the following which are really not errors, but just indicate that the RL is polling the network share.

14:40:49.660    61777    180.189804    {SMB:2897, NbtSS:6, TCP:5, IPv4:4}    172.20.10.2    172.20.12.60    SMB    SMB:R; Transact2, Find First2 - NT Status: System - Error, Code = (15) STATUS_NO_SUCH_FILE

However, if the following errors occur, there is a problem, and the receive location will be disabled.  You will see these in succession in the capture with the above filter.  In this case the errors continued to occur even after the receive location was moved to a UNC that was not a part of the Distributed File System Share.

14:40:50.613    61992    181.142929    {SMB:2910, NbtSS:6, TCP:5, IPv4:4}    172.20.10.2    172.20.12.60    SMB    SMB:R; Transact2, Query Path Info - NT Status: System - Error, Code = (860) STATUS_NETWORK_SESSION_EXPIRED
14:40:50.613    62008    181.142929    {SMB:2913, NbtSS:6, TCP:5, IPv4:4}    172.20.10.2    172.20.12.60    SMB    SMB:R; Transact2, Query Path Info - NT Status: System - Error, Code = (58) STATUS_OBJECT_PATH_NOT_FOUND
14:40:50.613    62013    181.142929    {NbtSS:6, TCP:5, IPv4:4}    172.20.10.2    172.20.12.60    SMB    SMB:R; Nt Transact, Unknown NT Transaction Function - NT Status: System - Error, Code = (288) STATUS_CANCELLED

This fix is for the redirector.  To resolve the error, apply this fix on each Biztalk Server.

http://support.microsoft.com/kb/944505