Calibration Error? Command denied, landed state is unknown?

I am using the SITL simulator on 192.168.2.81 that sends an --out=udp:192.168.2.91:14550 to Dronecode SDK running ./takeoff_and_land udp://192.168.2.91:14550. On the SITL, I’ve set:

param set ARMING_CHECK 0
arm uncheck all
arm safetyoff

I believe I’m able to connect but I’m getting these errors:

./takeoff_and_land udp://192.168.2.91:14550
[02:39:06|Info ] DronecodeSDK version: v0.13.0-dirty (dronecode_sdk_impl.cpp:25)
[02:39:06|Error] No known remotes (udp_connection.cpp:130)
Waiting to discover system...
[02:39:06|Error] send fail (dronecode_sdk_impl.cpp:91)
[02:39:06|Info ] New device on: 192.168.2.81:39576 (udp_connection.cpp:200)
Discovered system with UUID: 1
Discovered a component with type 1
Vehicle is getting ready to arm
[02:39:08|Error] Error: get param busy timeout: CAL_GYRO0_ID (mavlink_parameters.cpp:439)
[02:39:08|Error] Error: Param for gyro cal failed. (telemetry_impl.cpp:540)
[02:39:09|Error] Error: get param busy timeout: CAL_ACC0_ID (mavlink_parameters.cpp:439)
[02:39:09|Error] Error: Param for accel cal failed. (telemetry_impl.cpp:551)
Altitude: 0 m
[02:39:09|Error] Error: get param busy timeout: CAL_MAG0_ID (mavlink_parameters.cpp:439)
[02:39:09|Error] Error: Param for mag cal failed. (telemetry_impl.cpp:562)
[02:39:10|Error] Error: get param busy timeout: SYS_HITL (mavlink_parameters.cpp:439)
[02:39:10|Error] Error: Param to determine hitl failed. (telemetry_impl.cpp:586)
Altitude: 0 m
[02:39:10|Error] Error: get param busy timeout: MIS_TAKEOFF_ALT (mavlink_parameters.cpp:439)
Vehicle is getting ready to arm
[02:39:11|Error] Error: get param busy timeout: MPC_XY_CRUISE (mavlink_parameters.cpp:439)
Altitude: 0 m
[02:39:11|Error] Error: get param busy timeout: MIS_TAKEOFF_ALT (mavlink_parameters.cpp:439)
Flight Mode: Unknown
Altitude: 0 m
Vehicle is getting ready to arm
Altitude: 0 m
Altitude: 0 m
Altitude: 0 m
Vehicle is getting ready to arm
Altitude: 0 m
Altitude: -0.007 m
Altitude: -0.009 m
Altitude: -0.012 m
Altitude: -0.014 m
Vehicle is getting ready to arm
Altitude: -0.016 m
Altitude: -0.018 m
Altitude: -0.02 m
Altitude: -0.022 m
Altitude: -0.023 m
Altitude: -0.025 m
Altitude: -0.027 m
Altitude: -0.028 m
Altitude: -0.029 m
Altitude: -0.031 m
Vehicle is getting ready to arm
Altitude: -0.032 m
Altitude: -0.033 m
Altitude: -0.034 m
Altitude: -0.036 m
Altitude: -0.037 m

I’m not sure why the altitude seems to be going down. If i change the altitude in SITL, it seems to be able to read that telemetry data:

mode guided
arm throttle
arm takeoff 100

Here’s the output from takeoff_and_land when I do that:

Altitude: 2.133 m
Altitude: 2.629 m
Altitude: 3.143 m
Altitude: 3.673 m
Altitude: 4.214 m
Altitude: 4.765 m
Arm Result: Command denied, landed state is unknown
Flight Mode: Unknown
Altitude: 5.324 m
Altitude: 5.89 m
Altitude: 6.462 m
Altitude: 7.039 m
Vehicle is getting ready to arm
Altitude: 7.621 m
Altitude: 8.207 m
Altitude: 8.797 m
Altitude: 9.391 m
Altitude: 9.986 m
Altitude: 10.586 m
Arm Result: Command denied, landed state is unknown
Flight Mode: Unknown
Altitude: 11.188 m
Altitude: 11.794 m
Altitude: 12.4 m
Altitude: 13.009 m
Vehicle is getting ready to arm
Altitude: 13.619 m
Altitude: 14.23 m
Altitude: 14.841 m
Altitude: 15.453 m
Altitude: 16.067 m
Altitude: 16.683 m
Arm Result: Command denied, landed state is unknown
Flight Mode: Unknown
Altitude: 17.299 m
Altitude: 17.916 m
Altitude: 18.533 m
Altitude: 19.151 m
Vehicle is getting ready to arm
Altitude: 19.769 m
Altitude: 20.389 m
Altitude: 21.008 m
Altitude: 21.627 m

So I know that it’s able to read data. But I’m not sure if it’s able to send commands. In that output I’m also printing the result of tying to arm the vehicle and the flight mode. That seems to be an issue. I’m sure this issue stems from the prearm check errors mentioned above. I’m not sure how to fix this though.