Project that I worked on disappeared from the Library

Hi there,

Last night I worked on a video with a Library & project stored on an external SDD hard drive.
Editing went smoothly and only quitting Final Cut Pro 10.5.1 I disconnected the drive.

This morning when I load the Library, the project that I worked on was not there, only an offer to create a new project.

Is there any way to retrieve edited footage and what should I do next time to prevent it from disappearing?

Any tips would be highly appreciated.

Check in the library Smart Collections in projects. What was the project called? How long was it? Check your clips for Make to make sure you didn’t edit into a clip container.