When running Kindle Mate in the Windows virtual machines using Parallels Desktop, VMware Fusion or VirtualBox, due to the virtual filesystem limitation, users might encounter the error with the following message box:
Kindle Mate failed to load data file ‘KM2.dat’
Causes and Solutions:
This generally occurs when using Share Folder feature, for instance, you have enabled the option Share Mac user folder with Windows in the option Share of Parallels Desktop. Such a setting will ‘combine’ some user folders like Documents, Downloads across Mac and Windows for easy management purpose, however, many programs including Kindle Mate may not access some data file properly and behave unexpectedly.
Moving your Kindle Mate program folder to other non-shared locations or disable such a Shared Folder option will solve the issue.