What is Internal Cut Error #64?

[Anonymous]

I am working on an old 8.1 file under AC12. Very often the 3D window reezes and I receiive this message. When I press OK it reappeares again. I have to forceully restart AC and Windows shows AC is active.
I suppose it is a glitch in the 3D engine, because most of the time the model is ok in 3D.
Weird!

[Anonymous]

This trouble associated with broken wall inetsection or multiply SEO operations (two or more SEO operations has been applied by turn with some element).
Solution: First remove all SEO operations and then, reapply SEO at the same time.
Cheers.

[Erika Epstein]

There was a change by in how SEOs are done between 8 and 12.

[Anonymous]

Kliment,

This happened to me a month ago, with an old part.
Unfortunatelly, I don't remember what did I do to fix it, except it was a tiny change.
For myself, it was a library part problem, nothing to do with SEO.
3D model was correct, but an alert displayed each time in 3D & section.

There is this Wiki article (under construction) from Judit Boros, about error messages
http://www.archicadwiki.com/error%20messages
but nothing about "internal cut error 64"

And no way to email the author. Sorry, this is not of great help.
Waiting for the complete article.