I had the same issue that @JebNotFound, @Artyom and others have experienced (trajectory/impact not showing in map view) after reinstalls or installing new mods.
After inspecting the logs it turned out that my newly installed KSPCommunityFixes complained about missing a Harmony dll, installing it from here fixed the issue for me: https://github.com/KSPModdingLibs/HarmonyKSP
Hope this might be helpful to someone