I was working with V4.6 and have used a lot of Sessions by storing it with "Store Session" (in German Version "Sitzung speichern").
Now I have installed the V4.75. Now I can't restore the Sessions which I have stored with V4.6.
Furthermore the the Session-Handling in V4.6 was still comfortable and faster than this is in V4.75.
My suggestion for following versions: It should be possible to store Sessions without any Dialog (like V4.6 do).
PS: I've uninstalld V4.75 and using V4.6 again.
The session handling is much easier in 4.7.5 because it is supported by Explorer plugin. The dialog helps you to have all your session in Favorties list. So if you store a session you can find it now faster in Favorties. You can also add your old session here to have a faster access. Furthermore every file of a session is displayed in Favorties for fast access, it means, you don't need to open the complete session to get only one file of it.
If you don't like this, I can make this behaviour optional in next version of Explorer.
But something additional comes in my mind. There were a format change in sessions files. Maybe you need to convert your old files to support the new format. Have a look into the new standard session file of Notepad and add/remove the missing items.
I'm having a problem storing sessions (even new ones created in v4.75, as there was a problem loading ones created in previous versions) in the favorites. NPP crashes when I try to store a session in a favorites group.
Did you tried to create session with UNICODE names? If so, it is currently not supported!