There 4 iron blocks at bottom, 4 glass at top. When a player clicks the button at the top, the glass blocks disappear and the player descends But the glass blocks never re-appear and the lower button does not work to ascend. ** Double-space will let the player fly! **

I tried setting prevent-leave:true and if the player tries to walk off the iron blocks at the bottom, it says "Can't leave elevator in use" forever. Even if the play leaves the game and comes back, they cannot move and it says this message. The server needs to be restarted for the player to do move again.

Server startup:

10:32 PM [INFO] [Lift] Loading Lift v26
10:33 PM [INFO] [Lift] Enabling Lift v26
10:33 PM [INFO] maxArea: 16
10:33 PM [INFO] autoPlace: false
10:33 PM [INFO] checkGlass: true
10:33 PM [INFO] baseBlocks: {IRON_BLOCK=0.5}
10:33 PM [INFO] Lift v26 is now enabled!

Created sign at top:

10:36 PM [INFO] [Lift] Starting elevator gen
10:36 PM [INFO] [Lift] Base size: 4
10:36 PM [INFO] Scan glass block type: IRON_BLOCK
10:36 PM [INFO] Is not glass?: true
10:36 PM [INFO] Is not base?: false
10:36 PM [INFO] Scan glass block type: IRON_BLOCK
10:36 PM [INFO] Is not glass?: true
10:36 PM [INFO] Is not base?: false
10:36 PM [INFO] Scan glass block type: IRON_BLOCK
10:36 PM [INFO] Is not glass?: true
10:36 PM [INFO] Is not base?: false
10:36 PM [INFO] Scan glass block type: IRON_BLOCK
10:36 PM [INFO] Is not glass?: true
10:36 PM [INFO] Is not base?: false
10:36 PM [INFO] [Lift] Floor added: Location{world=CraftWorld{name=WorldAJ},x=-1387.0,y=24.0,z=-455.0,pitch=0.0,yaw=0.0}
10:36 PM [INFO] Scan glass block type: GLASS
10:36 PM [INFO] Is not glass?: false
10:36 PM [INFO] Is not base?: true
10:36 PM [INFO] Scan glass block type: GLASS
10:36 PM [INFO] Is not glass?: false
10:36 PM [INFO] Is not base?: true
10:36 PM [INFO] Scan glass block type: GLASS
10:36 PM [INFO] Is not glass?: false
10:36 PM [INFO] Is not base?: true
10:36 PM [INFO] Scan glass block type: GLASS
10:36 PM [INFO] Is not glass?: false
10:36 PM [INFO] Is not base?: true
10:36 PM [INFO] [Lift] Floor added: Location{world=CraftWorld{name=WorldAJ},x=-1386.0,y=24.0,z=-454.0,pitch=0.0,yaw=0.0}
10:36 PM [INFO] [Lift] Elevator gen took: 124 ms.
10:36 PM [INFO] non Valid previous destination
10:36 PM [INFO] [Lift] Completed sign update

On upper level, pressed button (player went to bottom just fine):

10:38 PM [INFO] [Lift] Starting elevator gen
10:38 PM [INFO] [Lift] Base size: 4
10:38 PM [INFO] Scan glass block type: IRON_BLOCK
10:38 PM [INFO] Is not glass?: true
10:38 PM [INFO] Is not base?: false
10:38 PM [INFO] Scan glass block type: IRON_BLOCK
10:38 PM [INFO] Is not glass?: true
10:38 PM [INFO] Is not base?: false
10:38 PM [INFO] Scan glass block type: IRON_BLOCK
10:38 PM [INFO] Is not glass?: true
10:38 PM [INFO] Is not base?: false
10:38 PM [INFO] Scan glass block type: IRON_BLOCK
10:38 PM [INFO] Is not glass?: true
10:38 PM [INFO] Is not base?: false
10:38 PM [INFO] [Lift] Floor added: Location{world=CraftWorld{name=WorldAJ},x=-1387.0,y=24.0,z=-455.0,pitch=0.0,yaw=0.0}
10:38 PM [INFO] Scan glass block type: GLASS
10:38 PM [INFO] Is not glass?: false
10:38 PM [INFO] Is not base?: true
10:38 PM [INFO] Scan glass block type: GLASS
10:38 PM [INFO] Is not glass?: false
10:38 PM [INFO] Is not base?: true
10:38 PM [INFO] Scan glass block type: GLASS
10:38 PM [INFO] Is not glass?: false
10:38 PM [INFO] Is not base?: true
10:38 PM [INFO] Scan glass block type: GLASS
10:38 PM [INFO] Is not glass?: false
10:38 PM [INFO] Is not base?: true
10:38 PM [INFO] [Lift] Floor added: Location{world=CraftWorld{name=WorldAJ},x=-1386.0,y=24.0,z=-454.0,pitch=0.0,yaw=0.0}
10:38 PM [INFO] [Lift] Elevator gen took: 70 ms.
10:38 PM [INFO] Elevator start floor:2
10:38 PM [INFO] Elevator start floor y:68
10:38 PM [INFO] Elevator destination floor:1
10:38 PM [INFO] Elevator destination y:26
10:38 PM [INFO] Number of entities in this chunk: 1
10:38 PM [INFO] Going Up: false
10:38 PM [INFO] Number of passengers: 1
10:38 PM [INFO] Elevator chunks: 1
10:38 PM [INFO] Total generation time: 251

NOTE: Standing on iron blocks at bottom, y=25. Standing on glass block at top, y=67 (this doesn't match with "Floor added" messages in log...

If the user clicks the bottom button at this point:

10:46 PM [INFO] [Lift] Starting elevator gen
10:46 PM [INFO] [Lift] Base size: 4
10:46 PM [INFO] Scan glass block type: AIR
10:46 PM [INFO] Is not glass?: true
10:46 PM [INFO] Is not base?: true
10:46 PM [INFO] Invalid block type
10:46 PM [INFO] Scan glass block type: IRON_BLOCK
10:46 PM [INFO] Is not glass?: true
10:46 PM [INFO] Is not base?: false
10:46 PM [INFO] Scan glass block type: IRON_BLOCK
10:46 PM [INFO] Is not glass?: true
10:46 PM [INFO] Is not base?: false
10:46 PM [INFO] Scan glass block type: IRON_BLOCK
10:46 PM [INFO] Is not glass?: true
10:46 PM [INFO] Is not base?: false
10:46 PM [INFO] Scan glass block type: IRON_BLOCK
10:46 PM [INFO] Is not glass?: true
10:46 PM [INFO] Is not base?: false
10:46 PM [INFO] [Lift] Floor added: Location{world=CraftWorld{name=WorldAJ},x=-1387.0,y=24.0,z=-455.0,pitch=0.0,yaw=0.0}
10:46 PM [INFO] [Lift] Elevator gen took: 30 ms.

(but nothing happens)

If someone then clicks on the top button:

10:48 PM [INFO] [Lift] Starting elevator gen
10:48 PM [INFO] [Lift] Base size: 4
10:48 PM [INFO] Scan glass block type: IRON_BLOCK
10:48 PM [INFO] Is not glass?: true
10:48 PM [INFO] Is not base?: false
10:48 PM [INFO] Scan glass block type: IRON_BLOCK
10:48 PM [INFO] Is not glass?: true
10:48 PM [INFO] Is not base?: false
10:48 PM [INFO] Scan glass block type: IRON_BLOCK
10:48 PM [INFO] Is not glass?: true
10:48 PM [INFO] Is not base?: false
10:48 PM [INFO] Scan glass block type: IRON_BLOCK
10:48 PM [INFO] Is not glass?: true
10:48 PM [INFO] Is not base?: false
10:48 PM [INFO] [Lift] Floor added: Location{world=CraftWorld{name=WorldAJ},x=-1387.0,y=24.0,z=-455.0,pitch=0.0,yaw=0.0}
10:48 PM [INFO] Scan glass block type: AIR
10:48 PM [INFO] Is not glass?: true
10:48 PM [INFO] Is not base?: true
10:48 PM [INFO] Invalid block type
10:48 PM [INFO] [Lift] Elevator gen took: 75 ms.

Can you post your config,yml for me.

Thank you for the detailed feedback.

maxLiftArea: 16 lowScan: 0 highScan: 255 debug: true autoPlace: false preventEntry: false preventLeave: false checkGlass: true floorBlock: GLASS baseBlockSpeeds: IRON_BLOCK: 0.5 STRING_oneFloor: There is only one floor silly. STRING_currentFloor: 'Current Floor:' STRING_dest: 'Dest:' STRING_cantEnter: Can't enter elevator in use STRING_cantLeave: Can't leave elevator in use liftSpeed: 0.5

Unable to replicate issue.