Ever see this in anomalie in xref'd dwgs?

I have seen it mostly in drawings that have been converted from dgn to dwg. It is an anomalie that emulates from the middle of the screen. It is these cone like blobs of white that change shape when you regen and shoot out from the center of the screen in different directions. I've been beating my head on how to get rid of this as it makes the drawing hard to read.
Anyone know what I'm talking about?
John

Can you select them?

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You can select the edge of one and it appears that a whole External Reference is selected. It's like a spot light on the ground being seen from high above in plan view. It's axis appears to be usually near the center of the drawing. Sometimes it has 3 or 4 separate spot light anomalie thingys.
John

JohnnyB wrote:
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JohnnyB wrote:
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maybe try setting PDMODE to 1

Usually these "objects" are 3 dimensional and have a start and end point on different Z planes. That is why you have trouble selecting them. Sometimes turning the drawing on its side in a 3D view will show these objects for what they are and make it easier to deal with them. Sometimes they were created in a civil package as a result of survey input. Depending on whether you need other objects that came in on the same layer you can try to isolate that layer and delete everything from it.