Hi, I'm having the same problems as mention below the error "Failed to open project. Check it is a valid Construct 3 single-file (.c3p) project." with all the latest addons. Any chance the file is not compactible with the latest C3 version?
That is most likely because you do not have the latest plugin versions. Can you hit f12 to see the console and see what error it is logging when it tries to open it? Also make sure you have the latest versions downloaded of each plugin.
