'[Project management] The selected project 'F:/FMP/Sp/body6.spp' isn't valid!'
when I try and open my project.
in my case, in the disk in which I had the project of substance, I no longer had space, and therefore, it did not allow me to save new versions of my file, now, I have moved the project folder to a place with more space, and I have not had problems. I hope it is helpful, greetings.