I worked a complete night in a project involving a research of my group. When I tried to open it today, it's blank, there are no layers at all. As you can see in this link the thumbnail in the home screen of the projects (it's the top one) looks normal, but when I open it, it's blank.
Can you open the .qgz project at this link, and maybe check its integrity and get a hint of what could be wrong?
I'm working with QGIS 3.2 in a Windows 10 64 bits. All my other projects are opening just fine.