The instruction manual that came with my gimbal said to download bgc2.2 bs from www.basecamelectronics.com/gownloads/8bit/
When I press the "connect" button, the program crashes and it generates a text file in the SimpleBGC_GUI_2_2b2 directory.

#
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000000006af484ee, pid=1036, tid=0x0000000000003058
#
# JRE version: Java(TM) SE Runtime Environment (8.0_381) (build 1.8.0_381-b09)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.381-b09 mixed mode windows-amd64 compressed oops)
# Problematic frame:
# C [libNRJavaSerial.dll+0x84ee]

I googled "libNRJavaSerial.dll+0x84ee" and it led me to this https://forum.basecamelectronics.com/index.php?p=/discussion/3319/simplebgc_gui_2_69b4-gui-is-shutting-down-automatically-after-connecting-to-extended-long-board/p1
whose main takeaway is to downgrade from the latest version of java to Java JRE 8 Update 231 https://www.filehorse.com/download-java-runtime-64/44197/

I did that, and it worked.

TL;DR: Don't use the latest version of java with this software and expect it to work. You need 231