Slack app for Jira Server stopped working on Dec 3rd

[Michael Woffenden]

Connection is broken and when re-entering credentials we see:

• H2_PRIOR_KNOWLEDGE cannot be used with HTTPS

This is the same day an update was released:

• Reliability: upgrade third-party HTTP client dependency

Help!

[Marcin Gebski · Accepted solution]

As per marketplace version listing at https://marketplace.atlassian.com/apps/1220099/jira-server-for-slack-official/version-history

Version 2.0.21 • Released 2021-12-06 • Supported By Atlassian • Free • Atlassian Closed-Source

Version 2.0.20 was mistakenly released with an option that forces a specific HTTP protocol when calling Slack that effectively breaks communications. This version removes such option.

Updating of an add-on should solve your problem.

[Michael Woffenden]

Thanks for the reply!  Have updated to the fixed version.

[Ilya Smirnov]

Same issue with Slack Server App