Installation hangs during “installing GRUB boot loader"

I’m trying to install OS (preferred Ubuntu bionic) for Socionext developerbox and the installation always hangs when “installing GRUB boot loader”.

I have the standard Synquacer kit.
1, mainboard (Socionext MZSC2AM rev 0.4)
2, 4GB DDR4-2400
3, 1TB hard disk (WD SATA)
4, display card (GEFORCE GT 710)

I install OS in accordance with the guide https://www.96boards.org/documentation/enterprise/developerbox/installation/ubuntu.html
1, download ubuntu 18.04 mini iso(network installer) into usb stick.
2, Boot into the installer and install

I did the workarounds according to the guide
1, [Hardware] Enable PCIe transaction size workaround
DSW3-2 is set to ON position
2, [Install] USB/PCIe networking (18.04 only)
Use USB network device

The installation freezes when showing “Installing GRUB boot loader” on the screen and the console output is as below.

Any help would be appreciated.

Try using an alternative workarond to the 64-bit PCIe transactions problem. Put DSW3 back to the default position and use approach #3 from the list of workarounds below just to run the installer (since it won’t matter that the installer doesn’t have accelerated 3D graphics). Once the install has completed you can reenable the DSW3 workarond to get 3D graphics working again.

Thanks a lot. It works after making that workaround.