I'm trying to import a xpz file on GX 15 U4 but no object is shown when I press LOAD button. Xpz file was exported on GX EV3 U11.
I have to mantain GX EV3 KB working on production while testing the same KB on GX 15, so new objects must be imported using xpz files.
Probably you have an User Control or Pattern that is not installed on the V15 U4. When you import, try to look at Output Windows. Certanly there is an error there.