Server crashes sometimes.

[17:02:21] [main/WARN]: Ambiguity between arguments [teleport, destination] and [teleport, targets] with inputs: [Player, 0123, @e, dd12be42-52a9-4a91-a8a1-11c01849e498]
[17:02:21] [main/WARN]: Ambiguity between arguments [teleport, location] and [teleport, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
[17:02:21] [main/WARN]: Ambiguity between arguments [teleport, location] and [teleport, targets] with inputs: [0.1 -0.5 .9, 0 0 0]
[17:02:21] [main/WARN]: Ambiguity between arguments [teleport, targets] and [teleport, destination] with inputs: [Player, 0123, dd12be42-52a9-4a91-a8a1-11c01849e498]
[17:02:21] [main/WARN]: Ambiguity between arguments [teleport, targets, location] and [teleport, targets, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
[17:02:21] [main/INFO]: Loaded 0 recipes
[17:02:21] [main/INFO]: Loaded 0 advancements
[17:02:21] [Server thread/INFO]: Starting minecraft server version 1.13
[17:02:21] [Server thread/INFO]: Loading properties
[17:02:21] [Server thread/INFO]: Default game type: SURVIVAL
[17:02:21] [Server thread/INFO]: Generating keypair
[17:02:22] [Server thread/INFO]: Starting Minecraft server on (Private information
[17:02:22] [Server thread/INFO]: Using epoll channel type
[17:02:23] [Server thread/INFO]: Preparing level "world"
[17:02:23] [Server thread/INFO]: Reloading ResourceManager: Default, bukkit
[17:02:24] [Server thread/INFO]: Loaded 524 recipes
[17:02:25] [Server thread/INFO]: Loaded 571 advancements
[17:02:25] [Server thread/INFO]: Preparing start region for level 0
[17:02:27] [Server thread/INFO]: Preparing spawn area: 4%
[17:02:27] [Server thread/INFO]: Preparing spawn area: 8%
[17:02:27] [Server thread/INFO]: Preparing spawn area: 12%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 16%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 20%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 24%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 28%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 32%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 36%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 40%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 44%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 48%
[17:02:28] [Server thread/INFO]: Preparing spawn area: 52%
[17:02:29] [Server thread/INFO]: Preparing spawn area: 56%
[17:02:29] [Server thread/INFO]: Preparing spawn area: 60%
[17:02:29] [Server thread/INFO]: Preparing spawn area: 64%
[17:02:29] [Server thread/INFO]: Preparing spawn area: 68%
[17:02:35] [Server thread/INFO]: Preparing spawn area: 72%
[17:02:42] [Server thread/INFO]: Preparing spawn area: 76%
[17:02:42] [Server thread/WARN]: Keeping entity minecraft:turtle that already exists with UUID 492e62b7-5b83-413f-9940-6d12915c7c65
[17:02:42] [Server thread/INFO]: Preparing spawn area: 80%
[17:02:42] [Server thread/INFO]: Preparing spawn area: 84%
[17:02:42] [Server thread/WARN]: Keeping entity minecraft:drowned that already exists with UUID 046e89dd-cb4b-452c-b4d4-c190aca00634
[17:02:42] [Server thread/INFO]: Preparing spawn area: 88%
[17:02:42] [Server thread/INFO]: Preparing spawn area: 92%
[17:02:43] [Server thread/INFO]: Preparing spawn area: 96%
[17:02:43] [Server thread/INFO]: Preparing spawn area: 100%
[17:02:43] [Server thread/INFO]: Time elapsed: 17311 ms
[17:02:43] [Server thread/INFO]: Done (19.819s)! For help, type "help"
[17:02:43] [Server thread/INFO]: Starting GS4 status listener
[17:02:43] [Query Listener #1/INFO]: Query running on 0.0.0.0:25568
[17:04:13] [User Authenticator #1/INFO]: UUID of player L2T is 06bee38d-3559-468f-9503-8492138f030f
[17:04:13] [Server thread/INFO]: L2T[/(Deleted, private information)] logged in with entity id 33 at (-1029.5533069327514, 73.875, -247.40761237341496)
[17:04:13] [Server thread/INFO]: L2T joined the game
[17:04:13] [Server thread/WARN]: Keeping entity minecraft:sheep that already exists with UUID 06f81a27-4a57-4fa6-bfd6-ace2305d23e0
[17:04:14] [Server thread/WARN]: Keeping entity minecraft:cow that already exists with UUID 612a82bc-2636-4b72-b931-636ffb4090c8
[17:04:14] [Server thread/WARN]: Keeping entity minecraft:wolf that already exists with UUID f179457e-09d5-4821-9588-40d23fe13cd9
[17:04:14] [Server thread/WARN]: Keeping entity minecraft:chicken that already exists with UUID c89619c4-d769-47c0-9ac1-7a810ef30dbd
[17:04:15] [Server thread/WARN]: Keeping entity minecraft:villager that already exists with UUID cf42043b-c214-4a56-b868-ea7968496470
[17:04:16] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 3827ms or 76 ticks behind