A remotely-initiated transfer that specifies a network file name in the UNC format (\\server\share\folder\file.ext) requires XCOM to establish a connection with the file server. This connection may fail so the transfer will fail with message "XCOMN0322E Cannot access file server: <reason>", where "<reason>" is the text associated to the Windows error code received by the connection attempt.
It has been observed sometimes that a transfer fails at the first attempt and works fine when retried immediately with the the same exact parameters.
Release : 11.6
XCOM establishes the connection to the file server by invoking function WNetAddConnection2() provided by the Windows API so that Windows manages the connection establishment.
Using a tool like Wireshark to trace the TCP/IP traffic between the Windows box and the file server for one of these cases revealed that, when the connection failed, Windows was not passing the domain name to the file server even though the transfer was running under the security scope of a domain userid. Windows passed the domain name when the connection succeeded.
Fix LU07574 improves the situation by two changes:
The fix sets the XCOM cumulative maintenance level to r11.6 SP03 22100.