Hi, I am upgrading J3 to J4 and would like to include a template that can work in J4 such as Simpli which can apparently work on both versions.
However I cannot install Simpli . When I try to install from Install & Update, first Joomla takes quite a long time and eventually
it stops and issues a warning:
Warning
JInstaller: :Install: Can't find Joomla XML setup file.
The Joomla package cannot be installed through the Extension Manager. Please use the Joomla! Update component to update Joomla.
