Looks like a macro related to the window niche object. If you are getting this, I assume it is from a PLA or something and not from a normal load of the same library that created the project in question?
Cheers,
Karl
One of the forum moderators AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB
Narrow your search down for the offending part by using a marquee of half of your model, then go to 3D window using marquee / selection. If the message pops up again halve the size of your marquee again. If it doesn't try the other half of your model, keep going with ever diminishing marquees till you find where the problem is.