Please follow the below steps and keep us posted:
1. Shutdown the original Virtual Machine (Do not suspend).
2. In Parallels Desktop menu bar go to File > New > Install Windows or another OS form a DVD or image file click Locate manually.
3. Tick Continue without a source and click Continue.
4. Choose appropriate OS > choose appropriate virtual machine configuration > tick Customize settings before installation.
5. Open the Control Center (Window menu > Control Center). Click on the cogwheel next to the original virtual machine to open its configuration.
6. Compare the setting of the new virtual machine settings with the original one. Set up all the new virtual machine settings like in the original one. Then close the original virtual machine configuration window.
7. In the new virtual machine's configuration go to Hardware tab > Hard Disk 1. Set the Source to Choose an image file.
8. Navigate to the virtual machine location directory (default folders are /Documents/Parallels/ or /Users/Shared/Parallels/, it can be different in your particluar case) and open your original virtual machine's .pvm bundle, choose .hdd file inside it. Also make sure that you got the same location type as it is in the original virtual machine configuration.
9. Close settings and complete the virtual machine installation. The new virtual machine will be started.
10. Please check if you are experiencing the same issue.
NOTE: You may follow this article till step 9.
11 If the issue still persists, please uninstall and reinstall Parallels Desktop 12.