...elements in the tree are grayed?

...an element is inserted automatically, although "Build assembly automatically" is not activated?

Parts with only one variant defined are integrated automatically with the insert command. In the example to the right, the part type "HNC_2" contains only one variant, i.e. "screw2". If you activate the insert screw2 (ex.) command, it is directly included in the assembly.

...an element in the directory tree is marked in red, but in the related table there are no variants?

The constellation selected by you does not provide for an appropriate part in this position of the assembly.

If you intend to export the assembly, you must first select another variant at a "higher" level of the structure so that there are no more parts in red letters.

	Note
	An assembly can only be exported if all directory elements are uniquely engaged.

...an element is marked in orange in the "Assembly" window?