Qt Creator randomly silently drops CMake

I'm pretty sure it happened to me at least once before on older QtC.

I've created a simple CMake project, worked on it just fine. Opened it another day and saw no code files. Only CMakeLists.txt. And QtC didn't react to anything. Clicking "Run CMake" did absolutely nothing (no output anywhere). It said my project was not configured. Tried reopening it, relaunching QtC, deleting shadow build and .user files, installed newer CMake, nothing helped. When I looked into the QtC CMake settings and noticed that there were no discovered cmake! It just somehow went away after I've restarted my PC. Specified it manually, reopened the project and now it's working again. I think I've encountered similar issue at least once before (sometime last year).
The total lack of diagnostics is what stumbled it. QtC could've at least produced "no CMake found" message.