A friend of mine tried to convince me that the expression "the doors is closing" is correct. It sounds completely wrong to me, but googling for it turns up some results.
In most contexts it would be ungrammatical in Standard English. However, it might properly occur if ‘The Doors’ was the name of a play that was coming to the end of its run.
This is basic grammar.
Door (singular) + is.
Doors (plural) + are.
The only time you could consider using doors with a singular verb would be if you were referring to the band The Doors:
(Although some would say "The Doors were a band....")