HP 3000 Manuals

HP Link Editor/XL Reference Manual

Internal Errors (4000-4999) 

Internal errors are errors caused by the link editor subsystem.  Internal
errors cause link editor commands to abort.  If you encounter any of
these messages, document the steps that produced the error, then report
the problem and error number to your Hewlett-Packard representative.

MPE/iX 5.0 Documentation