What is the size of your hard disk ? Maybe you're getting this problem:
The conversion job might fail if the disk size of the target virtual machine is less than but near 2TB
The conversion job might fail if the disk size of the target virtual machine is less than but near 2TB, with the folowing error message:
FAILED: A general system error occurred: Platform-specific error.Workaround: Decrease the size of the target disk so that it is not so close to 2TB or, if the disk is GPT, you can increase it above 2TB. It is verified that sizes smaller or equal to 2TB minus 512 MB works fine but sizes closer to 2TB might also work.