The disappearance of all of your desktop icons is due to a bug in the Vise installer/updater. This typically happens when someone has more than one version of Sonicfire Pro and runs the updater for Sonicfire Pro 3. The updater searches your computer for Sonicfire Pro to update. It finds Sonicfire Pro 2 and then attempts to install the update. Sonicfire Pro 2 cannot be updated so it fails. The installer bug then causes the permission settings for your desktop to change to "No Access". The next thing that happens is your icons begin to disappear.
Open the hard drive, click into your home directory and do a "Get Info" on the Desktop Folder. Change the permissions back to "Read & Write". That fixes the problem. Restart and the icons should show again.
Once that is fixed, run the updater again. This time take a moment to read each of the windows. You will be able to select the proper update path on one of them.