Extending your comment, this is the error in the command shell of flamenco-worker with two computers on Windows:
2020-06-10 14:56:33,328 WARNING flamenco_worker.runner.TaskRunner Command 0 of task 5ee0d876e5b84e87e6b7f458 was not succesful, aborting task.
2020-06-10 14:56:33,329 INFO flamenco_worker.runner.TaskRunner Aggregated task timing info: {}
2020-06-10 14:56:33,331 ERROR flamenco_worker.worker.FlamencoWorker Task 5ee0d876e5b84e87e6b7f458 failed
2020-06-10 14:56:33,334 INFO flamenco_worker.upstream_update_queue.TaskUpdateQueue Pushing task update to Manager, queue size is 2
2020-06-10 14:56:33,354 INFO flamenco_worker.upstream_update_queue.TaskUpdateQueue Pushing task update to Manager, queue size is 1
2020-06-10 14:56:36,435 INFO flamenco_worker.worker.FlamencoWorker.fetch_task Received task: 5ee0d876e5b84e87e6b7f459
2020-06-10 14:56:36,435 INFO flamenco_worker.worker.FlamencoWorker Task changed status to active, pushing to manager
2020-06-10 14:56:36,439 INFO flamenco_worker.worker.FlamencoWorker Updating task 5ee0d876e5b84e87e6b7f459 with status 'active' and activity Activity(activity='', current_command_idx=0, task_progress_percentage=0, command_progress_percentage=0, metrics={'timing': {}})
2020-06-10 14:56:36,450 WARNING flamenco_worker.commands.blender_render.(task_id=5ee0d876e5b84e87e6b7f459, command_idx=0) Error in settings: blender_cmd 'C:/Program' does not exist
2020-06-10 14:56:36,451 INFO flamenco_worker.worker.FlamencoWorker Task changed status to failed, pushing to manager
2020-06-10 14:56:36,452 INFO flamenco_worker.worker.FlamencoWorker Updating task 5ee0d876e5b84e87e6b7f459 with status 'failed' and activity Activity(activity="blender_render.(task_id=5ee0d876e5b84e87e6b7f459, command_idx=0): Invalid settings: blender_cmd 'C:/Program' does not exist", current_command_idx=0, task_progress_percentage=0, command_progress_percentage=0, metrics={'timing': {}})
2020-06-10 14:56:36,461 WARNING flamenco_worker.runner.TaskRunner Command 0 of task 5ee0d876e5b84e87e6b7f459 was not succesful, aborting task.
2020-06-10 14:56:36,463 INFO flamenco_worker.runner.TaskRunner Aggregated task timing info: {}
2020-06-10 14:56:36,465 ERROR flamenco_worker.worker.FlamencoWorker Task 5ee0d876e5b84e87e6b7f459 failed
2020-06-10 14:56:36,466 INFO flamenco_worker.upstream_update_queue.TaskUpdateQueue Pushing task update to Manager, queue size is 2
2020-06-10 14:56:36,482 INFO flamenco_worker.upstream_update_queue.TaskUpdateQueue Pushing task update to Manager, queue size is 1
2020-06-10 14:56:51,470 INFO flamenco_worker.worker.FlamencoWorker Updating task 5ee0d876e5b84e87e6b7f459 with status '' and activity Activity(activity='', current_command_idx=0, task_progress_percentage=0, command_progress_percentage=0, metrics={'timing': {}})
2020-06-10 14:56:51,481 INFO flamenco_worker.upstream_update_queue.TaskUpdateQueue Pushing task update to Manager, queue size is 1
This error has occurred on Windows with the same configuration that on Linux has worked, obviously changing the value paths to the correct ones.