Very strange behavior of SW - Never seen before

When I tried to open a drawing file today, I am getting the error message "An unknown error occurred while accessing D:\..\.....SLDDRW" and SolidWorks crashes.

It was working perfectly till yesterday and I did a lot of work in that drawing.

I can open all the reference part files and assembly files.

I can open the same drawing file in eDrawing.

Is there a solution someone can suggest to recover the drawing file to continue working.

There was no hardware or software change since yesterday.

I am working on Windows 8 64bit

Solidworks 2012 SP5

I appreciate if someone can suggest a solution and it will save lot of my drawing time.