Autodesk Sketchbook Pro is unable to open a .tiff file.

[Anonymous]

 I've been working on this piece for over a week with no issues. I draw, save, and pick it up the next day. But after last night, when I went to work on it, the file refuses to open. It shows as the Autodesk tiff file logo, and when i try to open it, i get an error message in the program. I've had this happen once before but it wasn't a big deal at the time because I had just started working on the file. Please help, I put a lot of time into this! I've tried some simple fixes but they havent worked.

[david.lau]

I am sorry to say that the file maybe corrupted.  I would try to use the "Save As" option . A nice feature is that is will use the last used file name and add a 1,2,3 after it.  i.e. File > Save As > Dragon.tif, File > Save As > Dragon2.tif,  File > Save As > Dragon3.tif, etc.