Summary:

• When installing a new Language Pack and set it as JIRA Default Language, the next time when the language pack is uninstalled, the language stays and did not actually changed to any other available language pack.

Steps to Reproduce:

1. Access the link below to get any additional language pack:
   • https://translations.atlassian.com/
2. Download any language pack.
3. Access JIRA and navigate to JIRA Administration > Add-ons > Manage Add-ons
4. Click "Upload Add-on" and select the recently downloaded language pack. Wait until it finish installing.
5. Navigate to JIRA Administration > System > General Configuraiton and click Edit settings.
6. Confirm that the new language pack is listed in the "Installed Language" and select the "Default Language" to it.
7. Navigate back to the "Manage Add-ons" page and uninstall the new language pack.
8. Return back to the "General Configuration" page and check the "Default Language"

Expected Result:

• The Default Language will auto adjust to another language as the current selected language before has been uninstalled.

Actual Result:

• The Default Langauge stay as it is even though the language has been uninstalled.

Workaround:

• Restart JIRA.
• Navigate back to JIRA General Configuration and change the language manually, the uninstalled language would not selectable anymore.