I will assume you doing a "Save As" and explain you.
Basically this is the file
Copy this file and paste it in new folder. So that it would be more clear
Now double click on it. And it opens and you able to run it.
Go back to the folder with the file. There you can see a folder created.
Basically .yxzp is a zip file. And when you opening it you are unzipping it.
In this folder you will have all the working files. It is configured on a relative path (i.e all files should in same folder.)
So basically if you do a Save As and save it some other location it wont work.
But if you do a Save it will be saved in folder and you can always come back and run it. And it should work.
Hope this solves your problem and gives you an understanding🙂
Hope this helps 🙂 Feel to ask if you have any questions