https://track.radensolutions.com/issue/NX-1745

The Web Console appears to work - as long as the files are roughly under 1MB in size (I could upload multiple 700kB files, but a single 1.2MB or larger files just lead to the OK button being greyed out indefinitely). Not sure if that's a Tomcat issue (though setting maxPostSize on the connector to 10MB didn't make a difference) or NetXMS simply not accepting anything larger for deployment.

I could not simply add folder name as root folder, I had to give the full path including drive letter, e.g. "C:\SomeFolder". Just entering "SomeFolder" did not work. That makes sense, as otherwise NetXMS can't possibly know which drive I might want that file on. Having said that, the Agent Policy does accept me entering "SomeFolder" as root folder and there is no hint or warning in the UI to tell me that this won't actually do anything.

When running Force deployment, this is in log:

2020.02.04 13:07:32.654 *D* [client.session.0  ] Received message CMD_POLICY_FORCE_APPLY
2020.02.04 13:07:32.654 *D* [client.session.0  ] Sending message CMD_REQUEST_COMPLETED (32 bytes)
2020.02.04 13:07:32.655 *D* [                  ] Job 45842 added to queue (node=3636, type=DEPLOY_AGENT_POLICY, description="Deploy policy TestFileDelivery")
2020.02.04 13:07:32.656 *D* [                  ] Template::forceApplyPolicyChanges(001-docker11): "TestFileDelivery" policy deploy scheduled for "001-docker11" node
2020.02.04 13:07:32.656 *D* [client.session.0  ] Sending compressed message CMD_JOB_CHANGE_NOTIFICATION (128 bytes)
2020.02.04 13:07:32.656 *D* [                  ] Job 45842 started
2020.02.04 13:07:32.803 *D* [node.agent        ] Node::createAgentConnection(001-docker11 [3636]): conn=0x7fb1360bc1c0
2020.02.04 13:07:32.803 *D* [agent.policy      ] FileDeliveryPolicy::deploy(001-docker11 [3636] from TestFileDelivery/TestFileDelivery):)
2020.02.04 13:07:32.803 *D* [agent.policy      ] FileDeliveryPolicy::deploy(001-docker11 [3636] from TestFileDelivery/TestFileDelivery): preparing file list
2020.02.04 13:07:32.828 *D* [                  ] Job 45842 finished, status=COMPLETED
2020.02.04 13:07:32.828 *D* [client.session.0  ] Sending compressed message CMD_JOB_CHANGE_NOTIFICATION (144 bytes)

Same after upgrading everyting to latest

NetXMS Server 3.1.343 - Ubuntu LTS 18.04.3
NXMC 3.1.343 - Windows 10
nxagent 3.1.343 - Ubuntu LTS 18.04.3

Also, if you set debug level on server and agent to 6, you could find some information in the log files. On server you can change that on the fly: nxadm -c "debug 6"
After changing debug level, you can perform "Force deployment of agents policies" and there should be something in the logs.

NetXMS Server 3.1-300 - Ubuntu LTS 18.04.3
NXMC 3.1.343 - Windows 10
nxagent 3.1-300 - Ubuntu LTS 18.04.3

Tried with your suggested settings, but still can't see any files on agent or in the NXMC dir after uploading to policy.
Im able to browse Node "File manager", upload files there and delete. So settings should be ok at Agent side.

For this function to work, filemgr should be enabled in agent configuration and root folder(s) should be set:

SubAgent=filemgr.nsm
[FILEMGR]
RootFolder=C:\

In current version all folders along the path should exists on the target system. In future versions agent will create folders. Files are only sent to agents, they are not deleted, when removed from policy / renamed in a policy.

If you edit agent policy, the settings will get applied (files sent to agents) the moment, when you close the list of agent policies. They should also get applied on configuration poll. And in context menu of template there's an option "Force deployment of agents policies".