If u have downloaded the latest beta release and u have exported the project to check it on a server, and now it does not work.
Then it is good to know its a beta release bug.
Solution:
Save your game as "project"
Then open the folder on your drive.
Then download Notepad ++
Then open the "your game name".capx
Then search for the line (<saved-with-version>8100</saved-with-version>)in the top of the file.
And change the number 8100 to 8002
Then save the file.
Go to Scirra release
Then download release r80.2
Install it
Then open the "your game name".capx u have just altered.
Then save it again as a single file to your drive.
Back it up!
Now u can export your games again and play them on your server.
Keep this in mind for the future beta releases.
And then just stay with the r80.2 release until this specific bug is fixed by the scirra team.