RPCs appearing as white rectangles and file cannot be saved

[alan]

Two issues that may or may not be related:

1.  In the attached ACA 2014 file, in the current walkabout view, a line of RPC trees appears as white rectangles when rendered, instead of as trees.  (If a bunch of RPCs are erased elsewhere in the model the problem does not appear.  The problem also disappears in other views.) 

2.  After opening nXt and rendering, upon returning to ACA2014, when trying to save the dwg file, this appears:

After performing a few undos it is possible to save without getting the message.

The RPC problem is similar to the widespread
one I had when the model was far from the origin, but now the model is at the origin.

I have repeatedly purged and audited - though Audit takes a relatively very long time.

 It seems I can sort of work around this but any help here would really be appreciated.

[alan]

I actually can't purge them even in the file you sent back to me.  No materials appear in the purge dialogue box at first.  After running nXt they do appear but can't be purged, even temporarily.

Anyway, I think I can manage with a new file and using nXt trees instead.

Thanks very much Garret.