# 6.0 Important Upgrade Notes

**URL:** <https://forum.mattermost.com/t/6-0-important-upgrade-notes/12037>\
**Category:** Announcements\
**Created:** [August 6, 2021, 2:28pm UTC](https://forum.mattermost.com/t/6-0-important-upgrade-notes/12037 "2021-08-06T14:28:30Z")\
**Posts on this page:** 1\
**Showing post:** 30

<div class="post-metadata">

**Author:** ![jurgenhaas](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mattermost.com/jurgenhaas/32/471_2.png) [@jurgenhaas](https://forum.mattermost.com/u/jurgenhaas)\
**Post date:** [December 22, 2021, 3:00pm UTC](https://forum.mattermost.com/t/6-0-important-upgrade-notes/12037/30 "2021-12-22T15:00:09Z")

</div>

I’ve just upgrade to GitLab 14.6 which comes with Mattermost 6.1 - update went through without any error message, but Mattermost service is not available. Looking into the log, I’m seeing these a lot:

```auto
{"timestamp":"2021-12-22 15:54:04.626 +01:00","level":"fatal","msg":"Failed to alter column type. It is likely you have invalid JSON values in the column. Please fix the values manually and run the migration again.","caller":"sqlstore/store.go:906","error":"pq: default for column \"timezone\" cannot be cast automatically to type jsonb","tableName":"Users","columnName":"Timezone"}

```

I believe that the GitLab installation uses PostgreSQL (version 12.7 in my case) and I have no idea what I need to be doing to fix this.

EDIT: found the solution in [PostgreSQL error when migrating from 5.39.0 to 6.0.0](https://forum.mattermost.com/t/postgresql-error-when-migrating-from-5-39-0-to-6-0-0/12303)

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