Vehicle not ready -- Issue with Pixhawk 4 Mission

I currently have an mRo PX4 set up in qgroundcontrol as a rover, and Iā€™m trying to test some basic missions on it, however, whenever I try to start a mission it says vehicle not ready. I have disabled a few safety checks that were preventing me from arming, however I am still unable to get run any missions.
Has anyone encountered this issue before?

ā€“JM

Is there any hint in the messages sent to QGC what is still wrong?

All the error says is unable to start mission: vehicle not ready. That only shows in the little yellow popup. I donā€™t see any other errors.

Whatā€™s your px4 version? What navigation system do you use? GPS?

itā€™s the mRo PX4 ā€˜Cool kitā€™ 2.4.6 I believe. That includes the GPS Iā€™m using for navigation.

2.4.6 is not a px4 firmware version, just because the last version is 1.10 for now.
You can check your version in QGroundControlsā€™s Summary screen in Airframe section of it.

Oh, didnā€™t realize you were asking for the firmware version. The firmware version is 1.9.2. Vehicle is the Aion Robotics R1 UGV.

Iā€™ve done some more testing and I got the mission to successfully start once, however repeating the same steps again today (the last test was last week) resulted in the same error again. No additional information was provided in the error message.

Try to type ā€œgps statusā€ to mavlink console when you get the error again.

I canā€™t do that right now, but while testing before it said gps 3D lock and there were always 8+ satellites showing on it.

Sometimes we have the similar error (ā€œvehicle not readyā€) with the 3D lock in a GPS widget, but in console we have ā€œNOT OKā€ status. If so, there could be a connection issues with GPS receiver.
You can also try to remove several checks into EKF2_GPS_CHECK parameter.

I will try that, thank you.

Just tried it and it says that the GPS is OK. Iā€™ve removed a lot of those GPS Checks as well. Is there anywhere to find a more detailed error message?

You also could type ekf2 status and look to local and global position validities.
And one more command is sensors status. This will show you if there is something wrong with on of your sensors.

I tried both of those things and all my sensors are reading as OK, my GPS is healthy and validated, and I am still getting the same error.
One time I simply turned on everything and tried to start a mission and it worked, however I am unable to replicate that result.

And do you have a valid ā€œhome pointā€ on your map just before you try to start a mission?
If you donā€™t, try to increase COM_HOME_H_T and COM_HOME_V_T to make the home point appear.

I do. I actually just solved the problem about 10 seconds ago. I disabled the GPS failure detection circuit breaker in the developer parameters. Iā€™m pretty confused as to why that worked since I had disabled the GPS checks in the parameter you suggested earlier.