Same here, same error, with MSP-EXP430G2ET with the G2553 on Mojave 10.14.6. Interestingly, the old G2 board with the G2553 works, using the downloadable drivers.
The G2ET works fine on my Powerbook, which is still on El Capitan 10.11.
This sucks because I'd hoped to use it in a class, and we ordered the G2ET because the G2 is no longer available.
Please repeat these steps again and do not cancel the installation process until it is done. It seems that it takes a long time on your machine and it might look like it hangs but that's not the case.
In the board manager click remove on the TivaC package.
Go to the directory C:\Users\andre\AppData\Local\Energia15\staging\ and delete all files and folders
Go to C:\Users\andre\AppData\Local\Energia15\packages\energia\tools\dslite\ and delete the folder 126.96.36.1996
Go to C:\Users\andre\AppData\Local\Energia15\packages\energia\hardware\ and delete the folder tivac
Now restart Energia
Start Energia and reinstall the TivaC package.