Suddenly can't deploy image - Error "Failed to Deploy to Disk 1"

We have a number of Acer Veriton M2611G PCs running Win7. For some reason, we cannot deploy an image. We get the error "Failed to deploy the image to target disk 1. Possibly, the disk size is less than the source image or the image may be corrupted."

We have tried creating an image with all volumes, only C:/, C:/ and Recovery, and other combinations. We get the same error every time. I'm wondering if it is related to the fact that none of the volumes listed are showing the "Act" flag that indicates it contains the MBR. When we reboot after the error and try to launch the OS, it doesn't detect a boot disk, and we have to install Windows fresh, install updates, etc. I really have no idea what is causing this. Any suggestions are welcome. See attached for the list of volumes and their flags.