I have tried multi times I can't get the zombies to spawn at night it says spawning  80 zombies and I do not seen any at all. 

{
  "Spawn Settings": {
    "Always Spawned": true,
    "Spawn Time": 19.0,
    "Destroy Time": 8.0,
    "Spawn near players": true,
    "Min pop for near player spawn": 15,
    "Min distance from player": 40.0,
    "Max distance from player": 80.0,
    "Zombie Settings": {
      "Display Name": "Scarecrow",
      "Scarecrow Population (total amount)": 120,
      "Scarecrow Health": 200.0,
      "Scarecrow Kits": []
    },
    "Chance Settings": {
      "Chance per cycle": 100.0,
      "Days betewen spawn": 0
    }
  },
  "Destroy Settings": {
    "Leave Corpse, when destroyed": false,
    "Leave Corpse, when killed by player": true,
    "Spawn Loot": true,
    "Half bodybag despawn time": true
  },
  "Behaviour Settings": {
    "Attack sleeping players": false,
    "Zombies attacked by outpost sentries": true,
    "Throw Grenades": true,
    "Ignore Human NPCs": true,
    "Ignored entities (full entity shortname)": [
      "scientistjunkpile.prefab",
      "scarecrow.prefab"
    ]
  },
  "Broadcast Settings": {
    "Broadcast spawn amount": true
  }
}​

I updated my config still not working
I am just trying to spawn more zombies at night and scare everyone from set times. 

{
  "Spawn Settings": {
    "Always Spawned": true,
    "Spawn Time": 19.0,
    "Destroy Time": 8.0,
    "Spawn near players": true,
    "Min pop for near player spawn": 1,
    "Min distance from player": 25.0,
    "Max distance from player": 55.0,
    "Zombie Settings": {
      "Display Name": "Scarecrow",
      "Scarecrow Population (total amount)": 150,
      "Scarecrow Health": 200.0,
      "Scarecrow Kits": []
    },
    "Chance Settings": {
      "Chance per cycle": 100.0,
      "Days betewen spawn": 0
    }
  },
  "Destroy Settings": {
    "Leave Corpse, when destroyed": false,
    "Leave Corpse, when killed by player": true,
    "Spawn Loot": true,
    "Half bodybag despawn time": true
  },
  "Behaviour Settings": {
    "Attack sleeping players": false,
    "Zombies attacked by outpost sentries": true,
    "Throw Grenades": true,
    "Ignore Human NPCs": true,
    "Ignored entities (full entity shortname)": [
      "scientistjunkpile.prefab",
      "scarecrow.prefab"
    ]
  },
  "Broadcast Settings": {
    "Broadcast spawn amount": true
  }
}​

I just came here to say the same thing. It looks like there's an NRE shortly after the loading of the plugin, which could the an indication of an issue. I reloaded the pluign 3 times just to be sure the NRE happened every time the plugin loaded. I've confirmed that they aren't spawning by using Radar and I don't see any.

09/30 11:46:11 | >>> o.reload NightZombies
09/30 11:46:11 | Unloaded plugin Night Zombies v3.4.0 by 0x89A
09/30 11:46:11 | Loaded plugin Night Zombies v3.4.0 by 0x89A
09/30 11:46:22 | NullReferenceException: Object reference not set to an instance of an object
09/30 11:46:25 | >>> o.reload NightZombies
09/30 11:46:26 | Unloaded plugin Night Zombies v3.4.0 by 0x89A
09/30 11:46:26 | Loaded plugin Night Zombies v3.4.0 by 0x89A
09/30 11:46:46 | NullReferenceException: Object reference not set to an instance of an object
09/30 11:46:53 | >>> o.reload NightZombies
09/30 11:46:53 | Unloaded plugin Night Zombies v3.4.0 by 0x89A
09/30 11:46:53 | Loaded plugin Night Zombies v3.4.0 by 0x89A
09/30 11:47:11 | NullReferenceException: Object reference not set to an instance of an object​

From the log file:

NullReferenceException: Object reference not set to an instance of an object
  at Oxide.Plugins.NightZombies+SpawnController+<SpawnZombies>d__15.MoveNext () [0x0009c] in <1063679627cd4f8aa2bc1d375d17d97f>:0 
  at UnityEngine.SetupCoroutine.InvokeMoveNext (System.Collections.IEnumerator enumerator, System.IntPtr returnValueAddress) [0x00026] in <fcaf289839f24125a059795f150fce14>:0 

I unloaded all plugins and then loaded Night Zombies and still get the same error. I also deleted the config and data file and same error.

After reloading my test server with no plugins, and putting the Night Zombies plugin back on the server, it's working. The only possibility is that the Nova Weather plugin (Harmony plugin) was interfering because that was still loaded before and that Harmony plugin also interferes with XDQuest, so it's a possibility. I'll load the rest of my plugins now just to confirm there's no further issue.

So i do not have the Harmony plufin or XDQuest So I am just trying to get the mod to fire at the correct time. I have set mine for 19.5 that should be in server 7:30 PM. 

I can't get anything to happen at all. 
I have not seen any errors at all. in my console. 

09/30 12:02:02 | Unloaded plugin Night Zombies v3.4.0 by 0x89A
09/30 12:02:02 | Shutting down compiler because no more jobs
09/30 12:02:02 | Compiler shutdown completed
09/30 12:02:02 | Loaded plugin Night Zombies v3.4.0 by 0x89A

I did change my config some but even with default they didn't spawn. 

{
  "Spawn Settings": {
    "Always Spawned": true,
    "Spawn Time": 19.5,
    "Destroy Time": 7.5,
    "Spawn near players": true,
    "Min pop for near player spawn": 1,
    "Min distance from player": 25.0,
    "Max distance from player": 55.0,
    "Zombie Settings": {
      "Display Name": "Scarecrow",
      "Scarecrow Population (total amount)": 150,
      "Scarecrow Health": 200.0,
      "Scarecrow Kits": [
        "ZombieNew"
      ]
    },
    "Chance Settings": {
      "Chance per cycle": 100.0,
      "Days betewen spawn": 0
    }
  },
  "Destroy Settings": {
    "Leave Corpse, when destroyed": false,
    "Leave Corpse, when killed by player": true,
    "Spawn Loot": true,
    "Half bodybag despawn time": true
  },
  "Behaviour Settings": {
    "Attack sleeping players": false,
    "Zombies attacked by outpost sentries": true,
    "Throw Grenades": true,
    "Ignore Human NPCs": true,
    "Ignored entities (full entity shortname)": [
      "scientistjunkpile.prefab",
      "scarecrow.prefab"
    ]
  },
  "Broadcast Settings": {
    "Broadcast spawn amount": true
  }
}

@BetterDeadThanZed

What I want to do is every night on my server a storm and fog rolls in and forces people back into there homes and tons of Zombies are out and about. I am not sure how to pull that off. 

I just removed everything and reloaded the night zombies all default and says loaded perfect and still nothing. 

Well now all I get is 

NullReferenceException: Object reference not set to an instance of an object

1000000000 Times this mod is bugged for sure. 

Thank you for reporting this, it should be fixed in the latest version.

0x89A

Thank you for reporting this, it should be fixed in the latest version.

Thank you seems to work good on my test server. 
2 Questions
1. Any way to trigger a sound when it starts and end?
2. Any way to trigger weather at the same time like Fog or Storms?

I updated the plugin. No errors but still no zombies spawning and no message saying that they spawned (I enabled the message). I did use a command to change the time on the server but I don't think that should affect it.

clumsyzombie

Thank you seems to work good on my test server. 
2 Questions
1. Any way to trigger a sound when it starts and end?
2. Any way to trigger weather at the same time like Fog or Storms?

Not yet, those are both features that I would have to add to the plugin. I'll put it on the to-do list.

Did the last update fix this for anyone? I'm still getting no zombies, no message and no error.

BetterDeadThanZed

Did the last update fix this for anyone? I'm still getting no zombies, no message and no error.

0x89A

Could you send me your config file?

Here ya go:

{
  "Spawn Settings": {
    "Always Spawned": true,
    "Spawn Time": 19.8,
    "Destroy Time": 7.3,
    "Spawn near players": true,
    "Min pop for near player spawn": 1,
    "Min distance from player": 40.0,
    "Max distance from player": 80.0,
    "Zombie Settings": {
      "Display Name": "Scarecrow",
      "Scarecrow Population (total amount)": 50,
      "Scarecrow Health": 200.0,
      "Scarecrow Kits": []
    },
    "Chance Settings": {
      "Chance per cycle": 100.0,
      "Days betewen spawn": 0
    }
  },
  "Destroy Settings": {
    "Leave Corpse, when destroyed": false,
    "Leave Corpse, when killed by player": true,
    "Spawn Loot": true,
    "Half bodybag despawn time": true
  },
  "Behaviour Settings": {
    "Attack sleeping players": false,
    "Zombies attacked by outpost sentries": true,
    "Throw Grenades": true,
    "Ignore Human NPCs": true,
    "Ignored entities (full entity shortname)": [
      "scientistjunkpile.prefab",
      "scarecrow.prefab"
    ]
  },
  "Broadcast Settings": {
    "Broadcast spawn amount": true
  }
}