CustomComboBox::getSelectedItem NPE in MekHQ-origin MML

[Dzlan]

Environment

MekHQ version is 0.48.0 Stable
Operating System is Windows 10
Java version: mekhqlog.txt does not appear to state the java version.
Running java --version in cmd shows the following
java 16 2021-03-16
Java(TM) SE Runtime Environment (build 16+36-2231)
Java HotSpot(TM) 64-Bit Server VM (build 16+36-2231, mixed mode, sharing)

Description

When I right click a mech in the hanger, and click on Customize > Customize in Mek Lab
The MekLab remains empty. The string in the top left saying "No unit loaded" disappears as well

Every time I attempt this in 1 sitting I'm met with the following error in the log file.
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException: Cannot invoke "java.lang.Integer.intValue()" because the return value of "megameklab.com.ui.util.CustomComboBox.getSelectedItem()" is null

Possibly related, I've had two missions within my contract that have spawned 0 enemies. I needed to generated the enemy force myself in Megamek. I havn't looked into errors or anything else however or saved at that point as I was new and still working out what is normal and what is not normal.

Please see attached log files for the full
megameklog.txt
mekhqlog.txt
megameklablog.txt