Error - Open Production Failed

I've spent about 4 days editing a video, but when I went to open it, it says Error - Open Production Failed.

I'm on a Samsung S10+, the image of the video is in the main menu screen but when I click on it, it fails to open.

I've logged out and back in, I've shut down and restated phone and I've duplicated the project and still fails. 

What can I do, or have I lost hours of work?

Thanks