I download the latest version of NopCommerce 4.2 and updated the database of the current site that was running version 4.1 with the upgrade script.
I then created a sub-domain site and copied the downloaded files (no source) in to the sub-domain site. I stepped through the install dialog and created a new database. the new site completed the install and the home page was displayed. I logged in and entered the Administration area and all the data are displayed properly.
I then published my modified version of the new version (adding a magnifier to the photos and other checkout totals, etc) into the sub-domain and pointed the modified site to my existing database. The new sub-domain site works fine. the administration also works fine.
I then published the same modified 4.2 code with the same database connection to my old domain location. The site works fine, however, the administration section is not displaying the data for manipulation. Noe of the link display the store information. I get a blank data section.