The cause of this was found to be an issue with the length of the user account name and computer name (which is similar to the computer's "Bonjour" name).

If for some reason you are unable to update your copy of Suitcase Fusion 2 (v13) to the latest version, or you are still having problems, you may change the computer's name as follows:

• Open System Preferences and go to Sharing.
• If You are not an administrator, click the "lock" icon to authenticate with an administrator user account.
• Change the computer name to something shorter and less complex. Extensis suggests a name of 20 characters or less, with no punctuation. (Dashes are acceptable.) For example, "BobMacBookPro", "artmac-5" or "MacMini4".
• Click the Edit button beneath the computer name. This displays the Bonjour name. Confirm that this has the same name, although it may be lower-case. It will have the suffix ".local" automatically appended. For example "bobmacbookpro.local", "artmac-5" or "macmini4.local"
• Click OK to confirm the change.
• Launch Suitcase Fusion 2(v13)

If Suitcase Fusion 2 (v13) still fails to launch, you might also need to shorten your user account name. For example "Representative Willis Chatman Hawley" may need to be shortned to "Will". This is configured in the System Preferences/Accounts

The total length of the naming convention that is used via Bonjour is a combination of the User Name and the Computer Name.