Revit Structure 2013 Fatal Error Problems

[Anonymous]

I have experienced on a few different occations a fatal error or revit time out while working in a central model in Revit Stucture 2013. This issue has occured several times in my office and no more that three users are working in the cental file at a time. My question is: when working in my central model, I have my autosave/auto sync set to 15 minute invervals and I do save everytime I am prompted. After each fatal error/time out/forced revit closure occurs, I have found that both my local file and the central file on our server are time stamp - saved at least an 1 to 1.5 hrs prior to the error occurance. Is there an explanation or known reason for loosing 1-1.5 hrs of work after a fatal error when the file is saving/syncing every 15 minutes? 

Any ideas, guidance, or reccommendations would be greatly appreicated!!! Thanks!

[Alaaeldin_Alsahli]

you cant find any backup file (project_name.001.rvt) 002.rvt etc ... in the same folder than your original file?

if not  

try this then

go to 

collaborate tab----Restore backup

and then browse in the same project folder localy or sever and then press open

[Alaaeldin_Alsahli]

how to 

http://www.youtube.com/watch?v=OCWe5hjWAzw

if doesnt work keep us updated