Why does My document disaapears when i click on fill and sign. what can i do?

This sounds like a known issue that Adobe is looking into - the more users that can supply information to the employees on the right team the better they can figure it out...

There are several forum threads on it - see if these look like the same issue (is your issue in Acrobat or Reader, these threads are on Acrobat/Reader Fill & Sign) and if so try adding a comment to one of these for a reply from the Adobe team member:

Fill & Sign Issues

Why does my document dissapear when I select  "fill & sign"?

Fill & Sign does not load the file and displays blank screen

Thanks,

Josh