Please accept our apologies for any inconvenience caused.
Unfortunately, Firefox and Safari both stopped supporting NPAPI plug-ins (such as Microsoft Silverlight and Adobe Flash) last week, and EPPI Reviewer 4 depends on MS Silverlight...
You can still run EPPI Reviewer 4 on a Mac using the legacy Extended Support Release of Firefox (Firefox ESR 52.9.0), available from https://archive.mozilla.org/pub/firefox/releases/52.9.0esr/mac/. (The British English version is located at the subdirectory https://archive.mozilla.org/pub/firefox/releases/52.9.0esr/mac/en-GB/.)
You can then install and allow the Microsoft Silverlight add-on, available from https://www.microsoft.com/getsilverlight/Get-Started/Install/Default.
We have a more extensive document on this, available via our manuals page at https://eppi.ioe.ac.uk/cms/Default.aspx?tabid=2933. (See the specific link https://eppi.ioe.ac.uk/CMS/Portals/35/Silverlight%20and%20web%20browsers_2.docx.)
NOTE - you can install two versions of Firefox, so you can install and run the newest standard version of Firefox from https://www.mozilla.org/en-GB/firefox/new/ whilst also installing and having available the legacy ESR release. (Unless you create multiple profiles, you will find favourites and histories shared between the two programs, though... We are currently creating a document on running multiple Firefox profiles, which I will send on to you as soon as it is available. However, in the meantime, I'd recommend backing up any existing Firefox favourites and the like before installing the legacy ESR version.
As mentioned, we should shortly have new videos and documents available online, covering the recent browser changes. We are also in the process of writing a new version of EPPI Reviewer that will work across all browsers and devices without the need for add-ons, meaning you will be able to use EPPI Reviewer on tablets, smartphones and computers.
We have also completed a purely web-based coding tool, that allows you to code or screen references via a web-only interface i.e. no add-ons are required, and it can be used on any browser or device. See https://eppi.ioe.ac.uk/eppireviewer-coding/home for the application, and this forum post https://eppi.ioe.ac.uk/cms/Default.aspx?tabid=2932&forumid=22&threadid=2218&scope=posts for details.
I hope this email / information helps, but do let me know if you require any further assistance.