No connection to agent

Hi all!

after an update of my checkmk server from version 1.6 to 2.1.0p26, I would like to updates my agents, too.
I got the agent for windows from my checkmk server, uninstall the old one and install the new version.

with the following command I would like to register the agent:

> cd "C:\Program Files (x86)\checkmk\service\"
> cmk-agent-ctl.exe register -s MY_CHECKMK_SERVER -i MEIN_CHECKMK_INSTANCE -U automation -P THE_PASSWORD -H HOSTNAME
> check_mk_agent.exe updater register

both commands were successfully executed
But the checkmk server shows now this:

Where is my mistake?

Is the problem still present? Usually, I only get “Empty output from host” if I directly run a service scan after installing the agent (so if it’s not done installing it in the background).
You can try the agent locally on the server by running check_mk_agent.exe test

yes the problem is still present:

the command check_mk_agent.exe test will give me a long output with many informations.

and after that, the error message is gone!

Can you explain, what was the problem??

Sorry for the late response.
I’m not sure why it works now, but the test generates an agent output. Good to hear, that it is working now! You can mark the solution, so the thread is marked as completed.