I do not know how to resolve this problem on my PC.
I have installed next applications earlier:
LG Bridge (1.2.64)
LG Flash (126.96.36.199)
LG Mobile Driver (4.5.0)
LG United Mobile Driver (188.8.131.52)
LG UP Common DLL ( 184.108.40.206 )
LG UP for LAB (220.127.116.11)
I have tried different ways to run LG UP or LG Flash on my PC.
I also downloaded next .KDZ files from the internet
M25010g_00_OPEN_CIS_DS_OP_0212.kdz (Android 7.x Nougat)
M25010e_00_OPEN_CIS_DS_OP_0420.kdz (Android 7.x Nougat)
I have used them in LG UP 1.14 with Win7. It was another computer.
LG UP after I have clicked on its icon asks about administrative permissions and then does not appear at all.
What is your working combination (OS, drivers, application and e.t.c.) ?