Gray 'shadow' in my sequence

[Cher7777]

Hi, for the past several days my VP has been crashing. Sometimes after a few minutes...sometimes right when I open the application. Always in the same project and none of my others. The corrupt file has this weird gray shading in the sequence and I'm wondering if that's the 'bug'? Has anyone else encountered this? How could I fix? I've spent a ton of time on this project and am just about ready to export it but can't because of the crashing. HELP!!