Issue Summary

This is reproducible on Data Center: yes

Steps to Reproduce

1. With UPM 6.0.8, configure UPM in offline mode as per Switching UPM to offline mode.
2. Upload a .obr file to install the add-on.

Expected Results

The add-on is installed successfully without any error in the UI or log file. This works with UPM 5.1.5.

Actual Results

In the UI, error "An unexpected error occurred. Refer to logs for more information" is shown immediately while the add-on is being uploaded. The add-on is installed successfully when the dialog box closes by itself followed by a page refresh.

• Sometimes, the add-on is not installed successfully but without obvious error in the atlassian-jira.log file.

Workaround

• For most of the add-ons, it's possible to unzip the .obr file and upload the .jar file or copy the .jar file to Jira_home/plugins/installed-plugins directory followed by a restart. Some .jar file might have dependencies on other jar file(s) in the same .obr file. For those add-on, all the .jar files should be included in the upload/copy.
• This is not reproducible with UPM 6.0.11 so far. Update UPM if Jira version is 9.6.0 and above.