Why does a garage door remote open the door successfully but when you try to close the door the remote does not work and the door must be closed using the wall control in the garage?

Most garage door opener manufacturers adhered to new federal guidlines imposed buy the government in the early 90's to include 2 safety devices in each opener to avoid crushing injuries. Most of them use photo eyes you might notice mounted towards the bottom 6 inches of the track that the garage door rides in, ( near the floor on either side of the door). These are used to detect if there may be an obstruction in the path of a CLOSING door. IF these photo eyes cannot see each other (the beam of infra-red light between them is interupted), the opener is programmed to allow the door to close as long as someone push and holds the wall button in throughout the downward travel of the door. This forces an individual to observe the downward movement of the door, thus, hopefully preventing an injury or property damage. Usually these photo eyes will have small LED lights on them. IF both LED lights are on, this means the photo eyes can see each other, if not, try adjusting or bending the brackets until they are lined up and lights can be seen on each photo eye. This is a very common problem. It sometimes only takes a slight bump to knock them out of alignment. If this doesn't work, make sure the wiring from the photo eyes up to the opener is in tact and connected securely. Don't worry about a shock, most openers use low voltage for this system.

Answer2 A hit it right on the head. but if somehow that still does not help, sometimes check to see the sensors are not dirty or sometimes have spider webs, that also causes a problem.

These are both correct you will also have some of them having problems during the day but not at night most of the time this is caused by the sunlight shining in on the receving side. Easy fix is to swap the sensors