I am not sure what would cause this in one specific file.
If it was affecting all files, I would have suggested updating video drivers, but not if it is just one file.
Can you copy & paste the lines (entire model) to a new file and keep working on it there?
May not be so helpful if you have a lot of view set up as these can't be copied from one file to another.
Barry.
One of the forum moderators.
Versions 6.5 to 27
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