Waypoints writing error MP 1.3.66

We have a simple issue with writing the wappoints of a mission, since we downloaded the Mission planner 1.3.66 build 1.3.7054. 36589 AMP copterV3.5-dev (02da4d58) We can show it on the video. It fails with a line. We did test it with 2 different PH4 systems, The error is also shown in video. What’s the solution to this?

Best Winfried