What version of OS X are you on? Have you recently upgraded to Yosemite? If so, did the volume change to Core Storage? Symantec Encryption Desktop is not compatible with Core Storage, and I know that has caused several issues for people.
The only other time I think I have seen that specific error code is with the software failing to properly identify the partition scheme on the drive, and Core Storage might be the cause of that. Usually, however, if Core Storage is in use, the product will not install.