Thanks for getting in touch and apologies for the game-stopping inconvenience. Yes, unfortunately there now is a specific problem for Mac users. Firefox has dropped all support for Silverlight (and all NPAPI plug-ins) and shortly after also the latest version of Safari – only just released by Apple – did the same. We knew about the change in Firefox, but Apple keeps their plans secret, so could only speculate about what will happen about Safari.
We are very busy writing a new version of EPPI-Reviewer that does not depend on Silverlight, the first release (limited to Coding-Only), is described here, but cannot replace the full application.
For now, the best solution is to instal a recent (but not "latest") version of Firefox: any version up to and including Firefox ESR 52.9.0 will run Silverlight and other NPAPI plug-ins.) Version 52.9 is available from https://archive.mozilla.org/pub/firef...0esr/mac/en-GB/ British-English version; other languages are available at https://archive.mozilla.org/pub/firef.../52.9.0esr/mac/.
We have a hastily written "how to" guide available in the manuals page, direct link is this. Firefox installation is described from page 12, the guide is not Mac-specific (we should have it ready early next week), but hopefully this will be enough for you to cover the gap.
With many apologies once again,