Tried 3 times today to upgrade from 3.4 to 3.6. Downloaded and attempted to install and all apparently went well; however when completed it wouldn’t open. Tried Running the line you quoted, but it wouldn’t run. When attempting to run Libre at the outset received 2 error msgs, but they wouldn’t copy so don’t know what they read.
Have completely removed Libre from the system along with Help which evidently took without difficulty using Revo Uninstaller. If you know of a method to properly complete the installation I have kept the 3rd install package for the moment, but won’t try downloading it again as have run out of space and speed on the net.