User on thread https://answers.unrealengine.com/questions/186928/landscape-collison-issues-recreatelandscapecollisi.html reported workaround did not fix error. Provided landscape for testing:
Landscape collision does not properly interact with characters. The character falls through, ignoring collision. This seems to happen primarily on steeply sloped surfaces.
Error not reproduced internally, but looks like it was originally fixed in 4.3, resurfacing in 4.6.
Error has been experienced in the wild by several users:
1) Landscape Mode / Manage/ Selection Tools / Go To Change Component Size
2) Set Resize Mode to "Resample (leave everything else the same)
3) Apply (this may take a few seconds)
4) When the process is complete/ build pathing if u have NPCs /
5) Save close the editor
6) Reopen editor / test / Player should no longer fall through the terrain
[Not reproduced internally]
User repro steps:
1) Manage Landscape
2) Edit Splines / Tools Setting / Deform Landscape to splines: All Splines w/ Use Auto checked
3) Rebuild Pathing
4) Now NavMesh builds correctly in the area where Players and NPCs used to fall through the terrain
5) Everything works fine until you close editor
6) Exit/ Restart the editor the same old problem reappears!
Head over to the existingAnswerHub thread and let us know what's up.