[Error] [Discord Death] {"message": "Cannot send an empty message", "code": 50006}

Can you share your config and remove the webhook token?

{
"GeneralSettings": {
"Announce": true
},
"BanSettings": {
"Color": "3329330",
"Enabled": true,
"WebhookUrl": "https://discord.com/api/webhooks/"
},
"ReportSettings": {
"LogToConsole": true,
"Alert": "",
"Cooldown": 30,
"Color": "3329330",
"Enabled": true,
"WebhookUrl": "https://discord.com/api/webhooks/"
},
"MessageSettings": {
"LogToConsole": true,
"SuggestAlias": false,
"Alert": "",
"Cooldown": 30,
"Color": "3329330",
"Enabled": true,
"WebhookUrl": "https://discord.com/api/webhooks/"
},
"ChatSettings": {
"TextToSpeech": false,
"Enabled": false,
"WebhookUrl": "https://discord.com/api/webhooks/"
},
"MuteSettings": {
"Color": "3329330",
"Enabled": true,
"WebhookUrl": "https://discord.com/api/webhooks"
}
}

This isn't the correct config for this plugin

{
"Display Options": [
{
"Webhook url": "https://discord.com/api/webhooks/",
"Killer Type": "Player",
"Victim Type": "*"
},
{
"Webhook url": "https://discord.com/api/webhooks/",
"Killer Type": "Animal",
"Victim Type": "Player"
}
],
"Death Message": {
"Content": "",
"Embed": {
"Enabled": false,
"Title": "{server.name}",
"Description": ":crossed_swords: {discorddeath.message} :crossed_swords:",
"Url": "",
"Embed Color": "#ff6961",
"Image Url": "",
"Thumbnail Url": "",
"Fields": [
{
"Title": "Victim Type",
"Value": "{discorddeath.victim.type}",
"Inline": true
},
{
"Title": "Victim",
"Value": "{discorddeath.victim.name}({discorddeath.victim.id})",
"Inline": true
},
{
"Title": "Body Part",
"Value": "{discorddeath.victim.bodypart}",
"Inline": true
},
{
"Title": "Attacker Type",
"Value": "{discorddeath.killer.type}",
"Inline": true
},
{
"Title": "Attacker",
"Value": "{discorddeath.killer.name} ({discorddeath.killer.id})",
"Inline": true
},
{
"Title": "Attacker Health",
"Value": "{discorddeath.killer.health:0.00} HP",
"Inline": true
},
{
"Title": "Weapon",
"Value": "{discorddeath.killer.weapon} ({discorddeath.killer.attachments})",
"Inline": true
},
{
"Title": "Distance",
"Value": "{discorddeath.killer.distance:0.00} Meters",
"Inline": true
},
{
"Title": "Entity Owner",
"Value": "{discorddeath.killer.owner}",
"Inline": true
}
],
"Footer": {
"Icon Url": "",
"Text": "",
"Enabled": true
}
}
},
"Debug Level (None, Error, Warning, Info)": "Warning"

You have the Embed Enabled field set to false and don't have any text configured in the content field. So this will create an empty message. What are you trying to do with the message?

i disabled cause of cmd spam,
what is supposed to go in content field?

There are no commands in DiscordDeath. You disabled the discord embed which is used to display the message. Content can be used to display only a text message if you don't want a big fancy embed.