Two products go by the name "LockDown Browser" (Web Assign LockDown Browser and Respondus LockDown Browser)
This document provides an overview of the two different LockDown Browsers.
If students need help downloading WebAssign's LockDown Browser, please send them this document: Downloading WebAssign’s LockDown Browser.pdf
If a student is using WebAssign's LockDown Browser and are getting an error, they will need to contact WebAssign for help: WebAssign tech help contact info
These resources might also be helpful:
Test WebAssign LockDown Browser Installation