Important Upgrade NotesΒΆ

  1. If you are upgrading a High Availability Cluster: When upgrading from 3.10 or earlier to 4.0 or later, you must manually add new items to the ClusterSettings section of your existing config.json. For more information about this, see the Upgrading to Version 4.0 and Later section of High Availability Cluster (E20).
  2. After upgrading from versions earlier than 3.9.0: Security related changes were made in 3.9.0 that cause invite links, password reset links, and email verification links in emails generated by your Mattermost server to no longer work. Team invite links that users copied from the Team Invite Link dialog are not affected and are still valid.
  3. After upgrading from versions earlier than 3.8.0:
  1. Changes were made in 3.8.0 that require a change in the proxy configuration. If you’re using NGINX:
  1. Open the NGINX configuration file as root. The file is usually /etc/nginx/sites-available/mattermost but might be different on your system.
  2. Locate the following line: location /api/v3/users/websocket {
  3. Replace the line with location ~ /api/v[0-9]+/(users/)?websocket$ {.

If you are using a proxy other than NGINX, make the equivalent change to that proxy’s configuration.

  1. Security-related changes were made that require you to verify settings in the System Console. In the GENERAL section of the System Console, click Logging and make sure that the File Log Directory field is either empty or has a directory path only. It must not have a filename as part of the path.
  2. Backwards compatibility with the old CLI tool was removed. If you have any scripts that rely on the old CLI, they must be revised to use the new CLI. For more information about the new CLI tool, see Command Line Tools
  1. After upgrading from versions earlier than 3.6.0: Update the maximum number of files that can be open:
On RHEL6 and Ubuntu 14.04
Verify that the line limit nofile 50000 50000 is included in the /etc/init/mattermost.conf file.
On RHEL7 and Ubuntu 16.04
Verify that the line LimitNOFILE=49152 is included in the /etc/systemd/system/mattermost.service file.
  1. Enterprise Edition only: After upgrading from versions earlier than 3.6.0:
  1. If you previously had values set for RestrictPublicChannelManagement and RestrictPrivateChannelManagement, the new settings for RestrictPublicChannelCreation, RestrictPrivateChannelCreation, RestrictPublicChannelDeletion, and RestrictPrivateChannelDeletion will take those settings as their default values.
  1. After upgrading from versions earlier than 3.4: If public links are enabled, existing public links will no longer be valid. This is because in earlier versions, existing public links were not invalidated when the Public Link Salt was regenerated. You must update any place where you have published these links.