Slack Import Shows Messages Transferred, But Channels Are Empty

Community Support
1

Hey Rocket Community,

This is my first post, so I apologize if this topic has been addressed. I am having issues with importing my Slack data to Rocket.Chat. The Import page states that the channels, users, and 17,995 messages were successfully transferred. I can confirm that the channels and users are present in the workspace. However, none of the messages appear in any of the imported channels — they are all empty.

Below are the steps that I took to import the Slack data:

Slack Export

  • Exported our Slack workspace from Slack Admin → Settings → Import/Export Data.
  • Received a ZIP file containing:
  • channels/ folders with messages.json
  • users.json
  • Other metadata

Preparing for Import

  • Verified the Slack export was in standard Slack JSON format.
  • Reviewed users.json to ensure user data was complete.
  • I did not modify message files, and the messages.json appeared valid with expected message structures.

Rocket.Chat Import Steps

  • In Rocket.Chat: Administration > Workspace > Import.
  • I chose Slack as the import source.
  • Uploaded the Slack export ZIP.
  • Channels and users were successfully imported and visible in the workspace.
  • Issue: No messages appeared in the imported channels. All channels were empty, but the import page states that the 17,995 messages were imported.

Looking for Guidance

  • Has anyone run into this issue before?
  • Are there known issues with message visibility after Slack import?
  • Where can I find logs to debug what the importer actually processed or skipped?

Any help would be appreciated, and I am happy to provide sanitized sample JSON or logs if needed.

Thanks!

Server Setup Information

  • Version of Rocket.Chat Server: 7.8.0
  • Operating System: Ubuntu
  • Deployment Method: Docker
  • Number of Running Instances: 1
  • DB Replicaset Oplog: N/A
  • NodeJS Version: v22.14.0
  • MongoDB Version: 7.0.15 / wiredTige
  • Proxy: Nginx
  • Firewalls involved: Yes

Any additional Information

Import Type Last Updated Last Status File Users Contacts Channels Messages Total
Slack July 15, 2025 11:34 AM Completed successfully slack-data-formatted.zip 68 0 5 17,995 18,068

image
image1572×237 6.48 KB

2

I have seen other issue here or in github.

Have a good search.

Rocket is ultra fussy about imports.

Check your logs for errors.

3

Hey Reetp,

Thanks for the response. I checked the logs, and I noticed that the logs seem to mention that the imported message has channels. Below is a small snippet of the logs that I found.

Thanks,

{“level”:40,“time”:“2025-07-22T17:13:26.419Z”,“pid”:1,“hostname”:“<container_id>”,“name”:“Slack Importer”,“msg”:“Mentioned room not found: thanksjosh”}
{“level”:40,“time”:“2025-07-22T17:13:26.433Z”,“pid”:1,“hostname”:“<container_id>”,“name”:“Slack Importer”,“msg”:“Mentioned room not found: blameslack”}
{“level”:40,“time”:“2025-07-22T17:13:24.303Z”,“pid”:1,“hostname”:“<container_id>”,“name”:“Slack Importer”,“msg”:“Mentioned user not found: hufflepuff”}
{“level”:40,“time”:“2025-07-22T17:13:25.135Z”,“pid”:1,“hostname”:“<container_id>”,“name”:“Slack Importer”,“msg”:“Mentioned room not found: ShortFatDogProblems”}
{“level”:40,“time”:“2025-07-22T17:13:25.274Z”,“pid”:1,“hostname”:“<container_id>”,“name”:“Slack Importer”,“msg”:“Mentioned room not found: clips”}

4

At a guess these sort of errors are the root of your issue and need fixing.