Unable to open project

Please help me with this, if you can.
I saved my project, as usual, using Scrivener for Windows, version 1.9.16. I shut down my computer and closed the program after saving. An hour later I am trying to open my project and I get this error message:
:The project could not be opened. The project you are trying to open was created or saved using a newer version of Scrivener than the one you are currently using. You will need to update Scrivener to open this file."
I have checked for updates and I have no updates available.

I am able to open all my other projects, just not the one I am actually working on. I have tried multiple ways:
File:recent projects and selecting
File:Open and selecting the Scrivener project folder for it
I also tried opening it from my Mac, since it is in dropbox, but the Mac only opens the template, no work that I have done.

In the file folder for the project I can find all the chapters written as rich text formats and have opened them all in Word, but now I will have to redo the whole project and transfer those files in.

Does anyone have an idea how I can open the project?
Thank you!