Hi Ciaran,
I have just installed the demo installer of the template Riley J4. and I get the following error messages (see screenshots):
1. that the installer contains version 1.1.12, i.e. Joomla 3.
2. Joomla CMS, solved with "Maintenance: Database ->update Structure".
3. web links, not solved.
Many thanks for your help
Regards KHK