On a fresh 5.3.0 site, installation of 4.0.47 fails with the following error:
"Error! Incorrect version sequence. Cannot upgrade to 4.0.47 Stable. jDownloads version 3.9.8.4. or newer should already be installed on Joomla 3.10 for this update. Please read the documentation or visit the support forum.
"
This message occurs with both the "upload package file" and "install from web" option
Hi
This does sound strange. My first thoughts are that you have a site that came from Joomla 3 and that somehow you are referring that database.
I will send you a PM (Private Message) as they are secure
Colin