I have a FrameMaker file that I worked on last week but FrameMaker won't open today. I get an "Unknown File Type" dialog with a selection of file types that I can use to specify the source of the file. But, it is a FrameMaker file. The file is located on a network server, not my laptop. I have not encountered this error before. I googled it, but I found only discussions from 2009 or earlier. I am using FrameMaker 12.