The Woodstock Shakespeare Festival’s 21st season opens with The Comedy of Errors, the bard’s shortest and one of his most popular comedies. The story of two sets of identical twins separated at birth and reunited as adults, it is one of his most farcical, with an abundance of slapstick, word play and puns. Bird-On-A-Cliff Theater Company will perform The Comedy of Errors outdoors on Woodstock’s Elizabethan stage.