I had a quick look at your file and unfortunately it seems that most of its contents are lost. Approximately the last 90% of the file consist of 0-Bytes only which means that there is no data to recover here.
The first megabyte (or less) is data, but its doubtful if any useful information could be extracted. PTC provides no means to repair defect file or at least give access to partially stored information.
Given the big file size my best guess is that to many / too large pictures bring the program down when it comes to saving the file.
I guess your only hope is a working backup so you don't have to start from scratch.
P.S.: All I could recover from you file were the two attached graphics, one of them only partial.