The new CheckMK V 2.4_p8 Agent make some trouble by register the agent on Windows Server 2012R2. On higher versions its works finde.
Bevor i update the CheckMK-Server from 2.3:platest to 2.4_p8.
CMK version:
2.4_p8
OS version:
CheckMK Server: ubuntu 22.04lts
Client (Agent): Windows Server 2012R2
**Error message:**
C:\Windows\system32>"C:\Program Files (x86)\checkmk\service\cmk-agent-ctl.exe" -vv register --trust-cert --hostname "SomeHost.Some.url" --server "CheckMKServer.some.url:8000" --site
COMPANY -U AgentReg -P CENSOREDÂł*5/6:-)
[2025-07-23 12:43:42.586062 +02:00] INFO [cmk_agent_ctl] cmk-agent-ctl\src/main.rs:16: starting
[2025-07-23 12:43:42.587913 +02:00] INFO [cmk_agent_ctl] cmk-agent-ctl\src\lib.rs:50: Loaded config from '"C:\\ProgramData\\checkmk\\agent\\cmk-agent-ctl.toml"', connection registry from '"C:\\Program
Data\\checkmk\\agent\\registered_connections.json"'
[2025-07-23 12:43:43.741343 +02:00] DEBUG [reqwest::connect] C:\Users\jenkins\.cargo\registry\src\index.crates.io-6f17d22bba15001f\reqwest-0.12.12\src\connect.rs:620: starting new connection: https://
CheckMKServer.some.url:8000/
[2025-07-23 12:43:43.751500 +02:00] ERROR [cmk_agent_ctl] cmk-agent-ctl\src/main.rs:35: Error registering existing host at https://CheckMKServer.some.url:8000/COMPANY
Caused by:
0: Calling registration endpoint failed
1: error sending request for url (https://CheckMKServer.some.url:8000/COMPANY/agent-receiver/register_existing)
2: client error (Connect)
3: unexpected EOF during handshake
Does anyone have an idea for a solution to this problem? V2.3_platest works fine before.
