Simple Memory Session ID Not supported

[Allan_Mattson]

Simple Memory Error in N8N verison 1.118.1

This question was previously asked but never answered due to lack of information...I'm getting the following error in the Simple Memory node... 

Issues:
The value "250e6677e34c4c1db0e307b8497fc712" is not supported!

Here’s how the node is configured…

{
“nodes”: [
{
“parameters”: {
“sessionIdType”: “={{($json.input?.sessionId ?? $json.sessionId).toString().trim()}}”,
“sessionKey”: “”
},
“type”: “@n8n/n8n-nodes-langchain.memoryBufferWindow”,
“typeVersion”: 1.3,
“position”: [
752,
672
],
“id”: “59b45af3-8302-4ac9-9808-6d18ae3359d6”,
“name”: “Simple Memory”
}
],
“connections”: {
“Simple Memory”: {
“ai_memory”: [

]
}
},
“pinData”: {},
“meta”: {
“instanceId”: “f832b37f2bbb38b358d60b244d4e55582ce2655ab9a8c7386b044659c082b167”
}
}

It appears to me that it just doesn’t like the value of 250e6677e34c4c1db0e307b8497fc712. Is it a length issue?

[Andre_Black_Scribe]

The issue is that sessionIdType expects a type selector, not the session ID value itself. Split your configuration:

{
  "parameters": {
    "sessionIdType": "customKey",
    "sessionKey": "={{ ($json.input?.sessionId ?? $json.sessionId).toString().trim() }}"
  }
}

The fix: Move your expression from sessionIdType to sessionKey. The sessionIdType field should be set to "customKey" to specify the type, while sessionKey holds the actual dynamic session ID value.

This separation resolves the “not supported” error you’re experiencing.