Unfortunately, Ubuntu is not a supported platform for ADMS. I can't say that is the cause but the ADMS environment uses numerous wrapper scripts to determine the machine type for locating the correct binaries and unsupported platforms often can't be mapped correctly. That could explain why amc can't be found. Have you tried this on a support platform?
The vacom error could be a symptom of the previous problem but looks like something that the product forum might help with.