The problem is in the instructions, which are way to short on how to properly mount the TV to the arm.  I  resolved it by discarding the instructions and turned to common sense solutions.  If this is improperly assembled the TV could fall.  You have to be sure to get the proper spread on the mounting brackets in order to have the right side clip on the outside of the TV mounting plate.  otherwise the TV could very easily become detached with disasterous results ending in injury to a person or the TV itself.However this mount is a bargain for the price and is well made.
Dave Powers