I’m not sure what the crucial problem is in Jean Dubuffet’s later production, but it is large enough to make this exhibition appear weak and the majority of its hundred or so paintings, and as many drawings and prints, barren in their good-natured, French-bourgeois dexterity. The exhibition began with the early works of the big “Hourloupe” cycle, 1962–74, and ended with “Mires” (Test patterns, 1983–84). These introductory and concluding works in the chronological installation were the only ones which escaped looking oddly dated; the “collections” (Dubuffet’s word) of the mid ’70s, the “Parachiffres