Exploring in 3D, Model disappears as i navigate.

[Miner]

This happened all of the sudden but when i explore in 3D, the model disappears wherever I go as if there is a bubble the camera is in and nothing within that bubble is visible.  When I walk around the model just disappears!  If I back up the model reappears.  Therefore I can't get too close to the building (about 50').  I did notice that if I look directly down the model reappears until I start to look back up again.

[Miner]

Here is a video of what I see when I explore the 3D window.

[4dProof · Accepted solution]

in plan view, if you zoom extents, does the plan seem to disapear? check each story with all layers & renovation filters on. If the model is too spread out (like some random thing got thrown out in space a million miles) it can cause glitches like this.

[Miner]

That fixed it!!  I had a wall that was 243,071' long! 

Thank you for the help