Hi Fabio; Sorry to hear you're running into this issue. Hopefully we can get this squared away here on the forums, otherwise we might need you to open a support ticket, though to look into this we'd need to know a few things.
Does this happen with all projects or just this specific one?
What type of content do you have loaded into the project (TREC, MP3, WAV, MP4, MOV, AVI, etc.)
Are any of your project or source files stored on a network drive, external hard drive, or in a cloud-synced folder (such as OneDrive, Google Drive, etc.)?