Hi @MartinE4. The process you need to follow involves backing up the virtual machine first, upgrading your Mac, then upgrading Parallels and then restoring the virtual machine backup on your Mac (strictly in the said order). I'll break down the steps as much as I can. Hope this helps:
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Step 1: Backup your virtual machine properly:
1. Use an external hard drive (which is what we always recommend for transferring/backing up virtual machine files). The file format of the external hard drive must be Mac-compatible [e.g., exFAT, Mac OS Extended (Journaled) etc.,]. See this article for more details.
2. Locate your virtual machine file.
3. Make a copy of this file and place the copy in your external hard drive.
Step 2: Upgrade your Mac.
Step 3: Upgrade Parallels Desktop.
1. Refer to this link to purchase a special Parallels version 12 upgrade license for which Parallels version 8 users are eligible.
2. Download and install Parallels Desktop 12 on your Mac.
Step 4: Restore and use the virtual machine file backup on the Mac.
1. Create a new folder in the user home directory [Macintosh HD -> Users -> (username)] and named it 'Parallels'.
2. Move the virtual machine file backup copy located in your external hard drive into the 'Parallels' folder you just created.
3. Finally, double-click on the virtual machine file copy in the 'Parallels' folder and run it (select 'Moved' when prompted to select between 'Moved' and 'Copied').
Last edited: Jun 22, 2017
