BuildManager

Error while running the chunk
  [string "mods/addons/BuildManager/ImportExport.lua"]:112: attempt to concatenate a nil value
  func: __concat, metamethod, line: -1, defined: C, line: -1, [C]
    func: ExportBuild, global, line: 112, defined: Lua, line: 111, [string "mods/addons/BuildManager/ImportExport.lua"]
      func: createWidget, field, line: 214, defined: Lua, line: 211, [string "mods/addons/BuildManager/Script.lua"]
        func: ShowMenu, global, line: 43, defined: Lua, line: 31, [string "mods/addons/BuildManager/Menu/Menu.lua"]
          func: ?, ?, line: 178, defined: Lua, line: 159, [string "mods/addons/BuildManager/Menu/Menu.lua"]