December CU shipped with a security fix which – by default – blocks deployments if the temporary storage location is not on the C-Drive.
To enable a different drive it is required enable it using powershell code like the following:
# specify the drive which holds the tempory folder
$farm.AllowedContentDeploymentTempFolderDirectories = "X:\"
You can identify the configured temporary files folder path in the Content Deployment Settings page in the Central Administration or by running the following PowerShell command: