verstellen
to block
To place an object in such a way that it blocks a path, a door, or the view.
Bitte verstell nicht den Notausgang mit den Kisten.
Please don't block the emergency exit with the boxes.

to block / adjust / disguise
Loading your saved state.
to block
To place an object in such a way that it blocks a path, a door, or the view.
Bitte verstell nicht den Notausgang mit den Kisten.
Please don't block the emergency exit with the boxes.

The verb is made up of 'ver-' and 'stellen' (to put/place). The prefix 'ver-' has several functions here: it can mean putting something in the wrong place (blocking), changing a setting, or presenting oneself falsely ('sich verstellen' — to pretend).
Wer hat den Stuhl mitten in den Weg verstellt?
Who blocked the path with the chair?
'Verstellen' (to block / adjust / disguise) is an inseparable verb. The prefix 'ver-' is not separated from the verb stem, not even in a main clause.
Er verstellt oft seine Meinung, um anderen zu gefallen.
He often misrepresents his opinion in order to please others.
The verb can be used transitively with an accusative object (to block something, to adjust something) or reflexively ('sich verstellen'), which means 'to pretend' or 'to act as if'.
Ich muss die Klimaanlage verstellen, es ist zu kalt.
I have to adjust the air conditioning; it's too cold.
In the meaning 'blockieren' (to block), 'verstellen' is often combined with objects that block access or visibility: 'den Weg verstellen' (to block the way), 'die Tür verstellen' (to block the door), 'den Eingang verstellen' (to block the entrance), or 'die Sicht verstellen' (to block the view).
Ein großer LKW verstellte die Einfahrt zur Garage.
A large truck blocked the driveway to the garage.
The combination 'seine Stimme verstellen' (to disguise one's voice) is a fixed expression. It means to deliberately speak differently so as not to be recognized.
Am Telefon verstellte er seine Stimme, damit ich ihn nicht erkenne.
On the phone, he disguised his voice so that I wouldn't recognize him.
to imagine / introduce
'vorstellen' and 'verstellen' look similar, but in these uses they mean different things. 'vorstellen' means to move something forward, or, with a clock, to set the time ahead. 'verstellen' can mean that something blocks the way or the view. It can also mean changing the setting of a device or clock, often without saying whether it is moved forward or back. Learners can easily confuse the words because only the beginning is different and both have to do with placing things or settings. Pay attention to the meaning: 'vor-' points forward or to a later time; 'ver-' can refer to a wrong or disruptive change.

Der Schrank verstellt den Eingang zum Keller.
The cabinet is blocking the entrance to the basement.
Bitte stell den kleinen Tisch etwas vor, dann kommen wir besser an das Fenster.
Please move the small table forward a little; then we can get to the window more easily.