Autodesk Inventor

[#1]

1) How Can I turn on 'Adaptive' option on the menu shown in attached picture for layout part? (in assembly invironment)

2) Which process or fault leads to that problem?

best regards

[#2]

You would need to open/modify the part within the assembly and reference geometry from another item within the assembly.

Double click on the part within the IAM, then create a sketch on the surface of the part and project geometry from another item within the IAM onto the sketch and then process the sketch with a modeling feature.

Generally one works the other way. You create parts that reference features from other parts. This turns on the Adaptivity for that part. We then turn off the Adaptivity when we are happy with our finished model. This improves system performance of the assembly/model.