I currently have 1.14 edition of Diablo II. I used to have it with a previous patch, and in that patch I could make a copy of my save game files, and go to Charsi and imbue an item. If I didn't like the item, I could use a different copy of the files to do another imbue until I got an item I liked. 1.14 doesn't either doesn't like this, or I doing something wrong, because when I try to load that copy character, I get an error message about the character being a bad version. Has anyone got any suggestions as to how to achieve this?

No idea. And I guess it's not speedrunrelated? :o

It used to be that you can just alt+f4 instead of save+exit and it wont save. then you can just load it back up and imbue again.. if this isn't fixed, then you can just try that.