Julie,

At the command line, you should see any relevant information as to why they weren't loaded.  AutoCAD probably detected file corruption in them.

--J

Here's the load.  I don't know what the two bold missing files are. Any advice?

Customization file loaded successfully. Customization Group: ACAD
Customization file loaded successfully. Customization Group: CUSTOM
Customization file loaded successfully. Customization Group: EXPRESS
Customization file loaded successfully. Customization Group: LANDFX

Opening an AutoCAD 2013/LT 2013 format file.
Regenerating layout.
Regenerating model.

ACAD.RX Error: Unable to find file "MZ"
ACAD.RX Error: Unable to find file "$"

AutoCAD menu utilities loaded.
Land F/X v.15.46.2019.5.23 loaded.  © Copyright 2019 Ecografx, Inc._.OPENDCL
OpenDCL Runtime [9.0.2.0] loaded

*Cancel*

Command: *Cancel*
_RIBBON
*Cancel*
COMMANDLINE

Autodesk DWG.  This file is a TrustedDWG last saved by an Autodesk application or Autodesk licensed application.

Command:

Those are benign messages, due to the way our F/X CAD ribbon integrates with the Acad one.  You can create a blank text file named acad.rx in the AutoCAD/support folder to make them go away.

But otherwise -- that command history shows nothing regarding any xrefs.  What does your xref palette show?

--J