Forza single player

I cant play single player anymore (no problem with multi)***
I bought(download) the game June 2014 from marketplace and played normally.
Τoday I tried to play it again but single player give me messages “clean disc” or “restart console”…Obviously this is downloaded content so I cannot clean the disc(!!)
I have already spoken with Microsoft tried everything(cache-connection) with last resort to erase and download again the game but nothings happen.
Can anyone help or just the single player is dead ?
Sorry for my English

*** Νow I discovered that I do not can play neither multiplayer

IS THERE here someone from the company to answer or I gave my money for a game that is useless now;

I have had issues in the past with a few games. Turns out that it was a hardware fault and nothing to do with the software.

Try moving the game to a different storage device.

Try running the game without the hard drive connected.

Try starting the game with no profile signed in.

Solution 3 no work.The game wont start without profile

I try the first…

Finally… the game does not start with any of the three solutions…I try everything twice

I lost my money and everyone from the company hiding and not answering

VAMOS Turn 10

Delete and re-download the game?