Pasted outside the crop region or the annotation crop
Text, tags, detail lines and other view-specific elements keep their relative position when pasted. If that position falls outside the target view's crop region or annotation crop, Revit reports that the selection is invisible. This is the most common case when copying a note or detail between plans with different crops.
In the target view turn off Crop Region and Annotation Crop (Properties or the View Control Bar), paste, move the elements where you need them, then turn cropping back on. Alternatively widen the annotation crop offsets with Edit Crop.
The warning appears only with annotations or details = crop or annotation crop is the first suspect.