help, my entire map is hidden and i can't unhide it

[joeyjumper]

all over my VMF file i see
hidden
{

}
how do i undo this?

every single visgroup box is ticked by the way

[HighVoltage]

Press U on the keyboard

[joeyjumper]

pressed just "u",
...
nothing happened.

want the VMF?

[HighVoltage]

In the view menu there are tools that can hide selected items, sounded like that's what happened and to unhide them they keyboard shortcut is U