Startup Failure: MDB_CORRUPTED: Located page was wrong type

[timfallmk]

Problem

When loading the plugin (from first start or with a reload) I get the following error in the AWS CloudFormation output logs.

I also get toaster popup error messages to the same effect.

Error - 9:19:15 PM] AWS CloudFormation client: couldn't create connection to server.
  Message: Request initialize failed with message: MDB_CORRUPTED: Located page was wrong type
  Code: -32603 

Steps to reproduce the issue

1. Enabled AWS Toolkit
2. Open VSCode/Cursor

Expected behavior

Plugin loads normally

System details (run AWS: About and/or Amazon Q: About)

OS: Darwin arm64 25.2.0 Visual Studio Code extension host: 1.99.3 AWS Toolkit: 3.86.0 node: 22.20.0 electron: 37.7.0

[timfallmk]

This appears to have been a Cursor version bug or caching issue. I'm no longer getting it after updating. Closing issue.

[timfallmk]

Getting this again. Only occurs in Cursor.

[lionello]

I'm getting this in VS code-insiders:

[Info  - 6:02:36 AM] AWS CloudFormation is now listening...
internal error, index points to a C998 page!?
[Error - 6:02:36 AM] Server initialization failed.
  Message: Request initialize failed with message: MDB_CORRUPTED: Located page was wrong type
  Code: -32603 
[Error - 6:02:36 AM] AWS CloudFormation client: couldn't create connection to server.
  Message: Request initialize failed with message: MDB_CORRUPTED: Located page was wrong type
  Code: -32603 

Version: 1.107.0-insider Commit: b1018f0c37cb5dc62bba1665f6d2821fff098646 Date: 2025-11-25T14:17:19.499Z Electron: 39.2.3 ElectronBuildId: 12825439 Chromium: 142.0.7444.175 Node.js: 22.21.1 V8: 14.2.231.21-electron.0 OS: Darwin arm64 25.1.0

[inQJeroen]

Im getting tsomething similar in windsurf: [Error - 07:09:47] Server initialization failed. Message: Request initialize failed with message: MDB_PAGE_NOTFOUND: Requested page not found Code: -32603

[speedhawk21]

Getting the same error in VSCode:

[Info  - 3:07:59 PM] AWS CloudFormation is now listening...
page 4032665985 not found error
[Error - 3:07:59 PM] Server initialization failed.
  Message: Request initialize failed with message: MDB_PAGE_NOTFOUND: Requested page not found
  Code: -32603 
[Error - 3:07:59 PM] AWS CloudFormation client: couldn't create connection to server.
  Message: Request initialize failed with message: MDB_PAGE_NOTFOUND: Requested page not found
  Code: -32603 

Version: 1.106.3 Commit: bf9252a2fb45be6893dd8870c0bf37e2e1766d61 Date: 2025-11-25T22:28:18.024Z Electron: 37.7.0 ElectronBuildId: 12781156 Chromium: 138.0.7204.251 Node.js: 22.20.0 V8: 13.8.258.32-electron.0 OS: Darwin arm64 24.6.0

[faisalraihan1441-commits]

Dear Brian,

Thank you for reporting this issue.

To assist us in debugging, could you please provide more details regarding your setup? Information such as your operating system version, AWS Toolkit version, and any relevant configuration settings would be greatly appreciated.

We look forward to your response.

Sincerely, Faisal Raihan

On Sun, Dec 7, 2025 at 5:25 AM Brian Schaper @.***> wrote:

speedhawk21 left a comment (aws/aws-toolkit-vscode#8350) https://github.com/aws/aws-toolkit-vscode/issues/8350#issuecomment-3621359034

Getting the same error in VSCode:

[Info - 3:07:59 PM] AWS CloudFormation is now listening... page 4032665985 not found error [Error - 3:07:59 PM] Server initialization failed. Message: Request initialize failed with message: MDB_PAGE_NOTFOUND: Requested page not found Code: -32603 [Error - 3:07:59 PM] AWS CloudFormation client: couldn't create connection to server. Message: Request initialize failed with message: MDB_PAGE_NOTFOUND: Requested page not found Code: -32603

Version: 1.106.3 Commit: bf9252a2fb45be6893dd8870c0bf37e2e1766d61 Date: 2025-11-25T22:28:18.024Z Electron: 37.7.0 ElectronBuildId: 12781156 Chromium: 138.0.7204.251 Node.js: 22.20.0 V8: 13.8.258.32-electron.0 OS: Darwin arm64 24.6.0

— Reply to this email directly, view it on GitHub https://github.com/aws/aws-toolkit-vscode/issues/8350#issuecomment-3621359034, or unsubscribe https://github.com/notifications/unsubscribe-auth/BXLKOIGQRIYYBTWASB6DGIT4ANQXTAVCNFSM6AAAAACMYWSKPOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMMRRGM2TSMBTGQ . You are receiving this because you are subscribed to this thread.Message ID: @.***>

[speedhawk21]

Here are the logs for AWS Toolkit and the associate Cloudformation service errors. Let me know if you need something else specific.

OS: MAC 15.7.2 (24G325)

AWS Toolkit Logs

2025-12-06 15:33:07.536 [info] Log level: info, beta=false
2025-12-06 15:33:07.536 [info] endpoints: retrieving AWS endpoints data
2025-12-06 15:33:07.536 [info] Telemetry product: AWS Toolkit For VS Code
2025-12-06 15:33:07.557 [info] Telemetry clientId: 34694f2e-64b5-4794-a262-018f2ad93da9
2025-12-06 15:33:07.557 [info] Telemetry sessionId: a1fd6743-7c38-4fb7-a1b1-a9f0c4305dbc
2025-12-06 15:33:07.600 [info] OS: Darwin arm64 24.6.0
2025-12-06 15:33:07.600 [info] Visual Studio Code extension host:  1.106.3
2025-12-06 15:33:07.600 [info] AWS Toolkit:  3.89.0
2025-12-06 15:33:07.600 [info] node: 22.20.0
2025-12-06 15:33:07.600 [info] electron: 37.7.0
2025-12-06 15:33:07.603 [info] initialized 'submitFeedback' command with default feedback id: AWS Toolkit
2025-12-06 15:33:07.610 [info] auth: Updating connection state of profile:default to authenticating
2025-12-06 15:33:07.761 [info] auth: Updating connection state of profile:default to valid
2025-12-06 15:33:07.768 [warning] Ec2MetadataClient failed to fetch token. If this is an EC2 environment, then Toolkit will fall back to IMDSv1: ProviderError: Unable to connect to instance metadata service [EHOSTUNREACH]
2025-12-06 15:33:07.781 [info] CloudFormation telemetry: choice=false, hasResponded=undefined, lastPromptDate=1763584700308
2025-12-06 15:33:07.781 [info] using cloudformationLsp service configuration: default
2025-12-06 15:33:07.781 [info] Found CloudFormation LSP provider: RemoteLspServerProvider
2025-12-06 15:33:07.786 [warning] AwsContext: no default region in credentials profile, falling back to us-east-1:
2025-12-06 15:33:07.795 [info] Remote debugging is initiated
2025-12-06 15:33:07.795 [info] smus: SMUS Connection: Clearing all cached clients
2025-12-06 15:33:07.795 [info] smus: Not in SageMaker Unified Studio remote environment, skipping user activity monitoring
2025-12-06 15:33:07.804 [info] Creating CloudFormation LSP manifest for prod
2025-12-06 15:33:08.619 [info] lsp: Finished preparing "cloudformation-languageserver" LSP server: '~/Library/Caches/aws/toolkits/language-servers/cloudformation-languageserver/1.1.0'
2025-12-06 15:33:08.648 [info] Found CloudFormation LSP executable: ~/Library/Caches/aws/toolkits/language-servers/cloudformation-languageserver/1.1.0/cloudformation-languageserver-1.1.0-darwin-arm64-node22/cfn-lsp-server-standalone.js
2025-12-06 15:33:08.722 [warning] command failed (not registered?): "aws.amazonq.refreshConnectionCallback"
**2025-12-06 15:33:09.256 [error] CloudFormation language server failed to start: {"code":-32603}**
2025-12-06 15:33:46.137 [warning] telemetry: invalid Metric: "aws_showExtensionSource" emitted without the `result` property, which is always required. Consider using `.run()` instead of `.emit()`, which will set these properties automatically. See https://github.com/aws/aws-toolkit-vscode/blob/master/docs/telemetry.md#guidelines
2025-12-06 15:37:12.395 [warning] telemetry: invalid Metric: "aws_help" emitted without the `result` property, which is always required. Consider using `.run()` instead of `.emit()`, which will set these properties automatically. See https://github.com/aws/aws-toolkit-vscode/blob/master/docs/telemetry.md#guidelines

AWS Cloudformation Logs (Source: AWS Toolkit)

[Info  - 3:33:09 PM] AWS CloudFormation launched from ~/Library/Caches/aws/toolkits/language-servers/cloudformation-languageserver/1.1.0/cloudformation-languageserver-1.1.0-darwin-arm64-node22
[Info  - 3:33:09 PM] AWS CloudFormation is now listening...
page 489136996 not found error
[Error - 3:33:09 PM] Server initialization failed.
  Message: Request initialize failed with message: MDB_PAGE_NOTFOUND: Requested page not found
  Code: -32603 
[Error - 3:33:09 PM] AWS CloudFormation client: couldn't create connection to server.
  Message: Request initialize failed with message: MDB_PAGE_NOTFOUND: Requested page not found
  Code: -32603 
[03:33:09 PM] INFO: [Init] AWS CloudFormation initializing...
    ClientInfo: {
      "name": "Visual Studio Code",
      "version": "1.106.3"
    }
    NodeEnv: "production"
    AwsEnv: "prod"
    aws: {
      "clientInfo": {
        "extension": {
          "name": "amazonwebservices.cloudformation",
          "version": "1.0.0"
        },
        "clientId": "11111111-1111-1111-1111-111111111111"
      },
      "telemetryEnabled": false
    }
[03:33:09 PM] INFO: [Init] 
    Machine: "darwin-arm64"
    Process: "darwin-arm64"
    Runtime: "node=22.20.0 v8=13.8.258.32-electron.0 uv=1.51.0 modules=136"
[03:33:09 PM] INFO: [TelemetryService] Telemetry disabled

[speedhawk21]

Could be related to this issue:

https://github.com/aws/aws-toolkit-vscode/issues/8353

[speedhawk21]

Appears to be fixed now.

[thejchap]

this helped for me: rm -rf /Users/<me>/Library/Caches/aws/toolkits/language-servers/cloudformation-languageserver