The below Custom action is running in Uninstall too. But you won’t pass the TARGET.INSTALLLOCATION property value in uninstall. So this is the issue here.
<Custom Action="**SetInstallLocationRootDirectory**" After="CostFinalize" />
Modify this Custom action to run in Installation only.
<Custom Action="**SetInstallLocationRootDirectory**" After="CostFinalize">Not Installed</Custom>