ubiquity install wizard crashes; cannot install ubuntu-MATE 18.04.4

[watchpocket]

I've tried several times now to install Ubuntu-MATE version 1804.4 from a live USB.

Every time I hit "install," nothing happens. A circle spins for a few seconds, then stops.


I get an error message saying that ubiquity has crashed.


In the terminal I checked for ubiquity using:

dpkg -l ubuiquity 
sudo apt update
sudo apt install ubiquity

and saw that the live USB already has the latest version of ubuquity, which is 18.04.14.14.

I have a System76 Wild Dog, 64-bit desktop workstation, 4-core Q9650 3GHz, 8 GB ram. It has a BIOS, not UEFI.


Graphics: PNY Nvidia GeForce GTS 450, driver v. 367.44.
OSs: Ubuntu-MATE 16.04 & 14.04. Drives: 2 960-GB Sandisk SSDs.

I want to install Ubuntu-MATE 18.04.4 onto one of the SSDs (A standalone 960-GB SSD in an enclosure, that I later want to move into the Desktop box and boot directly from.)


Here is some of the lengthy error message report:


ExecutablePath:
/usr/lib/ubiquity/bin/ubiquity


Package:
ubiquity 18.04.14.14


ProblemType:
Crash


Title:
ubiquity crashed with PermissionError in___init___(): [Errno 13]
Permission denied '/cdrom/.disk/info'




How can I get a functioning ubiquity in the live USB and get the install wizard to open so I can complete the installation?

[watchpocket]

SOLVED: My live USB drive itself had permissions enabled for user only.

I created read and execute permissions for group and other:

chmod go+rx /media/name-of-live-USB-stick