Using right-click, ctrl+z, or the deconstruction planner, certain crash site entities can't seem be removed once placed. Things which can be removed, can only be removed by ctrl+z or the deconstruction planner.
I can't see the pole, but I'm guessing it isn't removed since there isn't a red selection box when using the deconstruction planner.
https://youtu.be/CGPC9vjiCRE
In the beginning of the video, in the weapons section, it also looks like there may be a duplicate vehicle machine gun, judging by the tooltip information.
[0.17.68] Map Editor: Cannot remove some crash site entities
Re: [0.17.68] Map Editor: Cannot remove some crash site entities
Thanks for the report. That's working correctly: they are not mineable (have no mineable results defined) so you can't mine them. You *can* delete them if you switch to the entity editor.
If you want to get ahold of me I'm almost always on Discord.