MP plan upload unrealiable

I am using cube black and orange based fixed wing planes for mapping missions. Typical mission is anything from 300 to 700 waypoints and about 1 hour of flight time. I have seen quite annoying and dangerous problem with uploading waypoints to the plane. It goes like this:

  1. I choose plan → load file and hit write.
  2. Writing completes without errors.
  3. I read the plan back and realize that the old plan is only partially replaced by the newly uploaded plan. Usually about 100 to 300 waypoints get replaced by new plan.
  4. I hit write again.
  5. Writing completes without errors again.
  6. Read results correct plan.

This does not happen very often, I would say one out of 200 flights have this kind of unreliable behaviour. Connection quality doesn’t seem to matter. This has happened on both SiK radios and on straight USB connection.

Sadly due to human factors it is not always caught in time and few crashes have happened because of this.

What could be causing this? This problem has followed my drone work for years through different versions of cubes, arduplanes and MPs and windows laptops.

Do you have a MissionPlanner.log file from a failed write ?
Or any way to do a stable repro ?

I dont have logs. The write does not fail, it goes through like any succesfull write all the way to last WP# of the new plan.

And so far I have not found a way reproduce this, it just happens randomly.

yes i think the tlog from the upload process is required here.