1.1 How the Download Manager is built
1.2 Why the Download Manager does not run on certain Virtual Machines
1.1 The main issue with some VM configurations is that some don't configure GPU for direct access. Without direct access, the download manager won't work at all because it can't start the API or find any GPU it can use. Here is a thread which explains what needs to be done.
1.2 Most of the times, if you open the Task Manager in the Virtual Machine, the GPU would not be listed