How do I install the updated Logix driver on 7.8?

Ignition 7.8.
Logix driver: 2.8.2 (b2016030813)
PLC: A-B ControlLogix 1756-EN2T/D.

I've just hooked up today and am reading bools OK. When I try to read a REAL via the OPC Quick Client I get

[Bad_CommunicationError] A low-level communication error occurred.

Q1. Is there some issue that might be fixed in the latest Logix driver, Allen-Bradley Logix5000 Driver Module (v21 support) Logix Driver-module.modl (3MB), Version: 3.9.6?
Q2. How do I upgrade (after I've downloaded it)?
Q3. Will it run without the two hour shutdown on my 7.8 installation?

Many thanks.

There's been fixes, but nothing I could say would help with the information you've provided.

You can't install the version from 7.9 into your 7.8 gateway. Your best bet here is to find the last version of 7.8 we released in the archives on the downloads page and upgrade to that.

For a system that's "just connected", I'd immediately ditch v7.8. Deploying a new install with a non-LTS version is just crazy.