I can't open old project

I had TB Studio Trial installed, then paid for TB Studio 7.1
I get Errror E1002 when opening it , its a movie, two drawing layers,one I rotoscoped on . The error informs me one drawing layer is missing. I am not aware of having moved or renamed, deleted it .

I have uninstalled TB Studio trial, error still there , nothing visible in the camear view now, all the rotoscoping I did is not visible , its a bit of a disaster for me
Fortunately, I had exported a movie already , but at this stage can do nothing more with this project :’(

I find it really frustrating not being able to save incremental updates, if this happened in other software, I would have yesterdays work to go back to
, or whenever it last worked