No existent collision prim?

[RainbowSuccubus]

So i have a small part of my mainland that you cant walk on, it makes you walk above like there is a invisiprim, but nothing shows up, last time it was my neighbors wall but that was fixed so idk now.

[Lindal Kidd]

If there is a hollowed-out prim whose physics type has been changed to "convex hull" it can produce invisiprim-like effects.  You wind up walking on/interacting with the simplified physics collision envelope, which does not follow the hollowed out parts of the prim.

[Chic Aeon]

22 minutes ago, RainbowSuccubus said:

So i have a small part of my mainland that you cant walk on, it makes you walk above like there is a invisiprim, but nothing shows up, last time it was my neighbors wall but that was fixed so idk now.

 

Looks like a bad physics model maybe? Either the landform (most likely) or possibly the big rocks.  If you use Firestorm you can SEE the physics model by opening the build menu to the FEATURES tab. Make sure that the "eye" icon is set to ON to see. 

In the shot below see how the physics model (yours may be blue especially if there wasn't really a physics model made) follows the shape of the hills?  That let's you WALK on the hills. If that wasn't done, the hills are just for looks. You can turn the landform to phantom to get to the ground but of course you won't be able to walk correctly on the hilly areas.

 

It that is actual LAND then it must be the rocks that are causing the issue. You could try turning them phantom and see if that helps. 

 

Edited March 10, 2020 by Chic Aeon
adding info

[Pussycat Catnap]

The last possibility is a ghost-prim.

Years ago we used to get these a lot - the physics engine of SL would think something was there, the rest of SL wouldn't. Often because something had been deleted from the area but a glitch had left a record of it behind...

Last time I saw one of those was in 2010...