I selected a component (double left click) and then did a right click, Hide.
Now I can not unHide it ! Edit → unHide → All or Edit → Select All → Edit → unHide → Selected has no effect !
I selected a component (double left click) and then did a right click, Hide.
Now I can not unHide it ! Edit → unHide → All or Edit → Select All → Edit → unHide → Selected has no effect !
Double clicking on the component would have opened it for editing. Very likely you opened the component and hid the geometry inside it. Open it again and you should be able to use Edit>Unhide>All to unhide the contents.
If you want to hide a component, don’t open it for editing first. Single click on it to select it and then right click and choose Hide.
As a first step, choose View->Hidden Geometry so that you can see the entities involved. Then try to select them. If you can’t, as Dave says they are no doubt nested inside a Group or Component. You will have to open that Group/Component for edit (perhaps nested Groups or Components) and then unhide them.
This sort of confusion is one of the reasons the experts recommend against using hide. It’s capability to manage things is very limited.
Hide and erase are perilously close together in the context menu. Try undoing (ctrl-z) a number of steps and see if it reappears- If it does, copy it, then redo (ctrl-y) all your edits, then paste it in place.