Assembly3 - position multiple instance of the same part and other issues/best Practice

[realthunder]

Highlight is wrong, but also constraints solving fail with this message, as if it does not take the plane in account but the body

The exact cause of this is hard to determine. I did fix a problem related to OriginFeature update during document restore. For now, you can manually fix this problem. First, make sure asm3 workbench is active. Locate the problematic constraint, expand it and find the ElementLink that shows the wrong shape, right click the item, select 'Link actions -> select linked object', which will jump to the Element object, right click the Element object item, and select 'Recompute object'. Then go back to the top assembly file, and recompute everything.