I really appreciate you and your team to helping me fix the file. There is nothing that missing in recovered version.
I don't know if this answers your question. About master pages, I set master pages for being the template by putting the logo at the bottom and creating "session number" on the top right corner. And then I apply it almost every page by pushing the shift button and click pages that I want to apply and then I edited the number of sessions in pages by double click it on the pages, not the master pages.
I will send the previous version file to you via PM.
if you require any further information, feel free to contact me.