Echelon Neuron - Manual (Page 170)

162 Common Command Line Errors (UCL)
UCL# Description
4003 Skipping <file> to avoid endless recursion [UCL#4003]
Command file recursion. A loop condition was detected when parsing
command files, and the file named in the warning message was excluded
from repeated processing to prevent an endless command file loop to occur.
4004 The content of this warning is user-defined. A warning message has been
specified by the UCL client, using the --warning command. The message
content is controlled by the caller (a command script, for example), and not
under control of UCL.