The Canon 5D Mark IV was first supported in Lightroom 6.7. Earlier versions cannot read those Raw files - and never will. There are no new camera updates for earlier versions.
Another (free) option is to download the free standalone DNG converter from Adobe and convert all your Raw files to DNG format. You will then be able to open those DNG files (not the Raw files) in Lightroom 5 or 6.
Hi Thanks so much I read this in the support forums and online and that is
why I downloaded the trial of Lightroom 6. So is it that the trial is just
the basic 6 and not updated to 6.7?
On Fri, Oct 12, 2018 at 9:58 PM John Waller <email@example.com>
So is it that the trial is just the basic 6 and not updated to 6.7?
Possibly. I don't work for Adobe and have not used Lightroom 6 for about 2 years (I'm using Classic CC) so I've no idea which version the Lightroom 6 trial delivers.
In Lightroom, click Help > System Info and the first line will tell you exactly which version you have installed.
Thank you so, so much for all your help.