How do I get all selected files to open in the same window?

I use Image Expert to open and edit photo files. First I open Image Expert. Then I go to the files I want to open. Before I upgraded to Windows 10, using the Control key as always I could select up to (at least) ten jpegs and choose "open". All of them would open in the same Image Expert window, which I NEED TO HAPPEN. Now with the upgrade, rather than getting ten pictures in one Image Expert window, I get ten Image Expert windows with one picture each! I need to be able to compare multiple photos right next to each other: this makes it impossible.

The only way I can find to get all pictures in one Image Expert window is to right-click each picture individually and then find "open" or "open with" in the options window and click that too. If I am opening, say, ten pictures that is now twenty clicks plus a lot of mouse action. Aint nobody got time for that! Is there a way to do this or am I going to be irritated for the rest of my life?

Note: The folder options do not have an option that says "open all files in the same window."

Help?

Hello :)

This may be something you need to feedback to "Image Expert". It reads as if the File>Open menu in Image Expert is not working correctly, the program may need to be updated for W10.