Exclude "Rayman Legends.exe" file to the DEP protection. DEP refers to Data Execution Protection. You're encountering an error because the file is blocked from execution.
1. Right click My Computer desktop icon.
2. Select Properties.
3. Click "Advanced system settings" on the left hand panel.
4. A new dialog will open. Click Advanced tab | Settings (Performance) | Data Execution Prevention.
5. Select the second option named "Turn on DEP for all programs and services except those I select".
6. Click Add button, locate the following file:
C:\Steam\SteamApps\Common\Rayman Legends\Rayman Legends.exe
7. Click OK twice and close the window.
Another important thing is the system settings. You'll start full scan with
this utility and fix all errors detected. When you're finished repairing, please restart your computer.