I met the same problem as GanLan met. I trying to open the project : Sgfx_ModemAT (B-L072Z-LRWAN1)
I proceed as explained in this post, But I could’nt build my project.
Also, I can not reach the folder < workbench_installation_folder >/plugins/fr.ac6.mcu.externaltools.arm-none.win32_< version_number >/tools/compiler/bin
Any imcome form your part will be welcome.