Nextcloud extension cannot be installed on a domain in Plesk: Unable to download file

Symptoms

Nextcloud extension cannot be installed on a domain:

PLESK_ERROR: Unable to download file: https://download.nextcloud.com/server/releases/nextcloud-30.0.3.zip

Cause

Nextcloud team withdrew the new version from their repositories and now it is not available until further notice:

• https://help.nextcloud.com/t/28-0-13-and-30-0-3-withdrawn/211672

Resolution

1. Connect to your Plesk server via SSH.

2. Download the hotfix:

   # wget https://support.plesk.com/hc/en-us/article_attachments/28441021049751 -O Releases.zip

3. Unzip the file:

   # unzip Releases.zip

4. Rename the original Releases.php file:

   # mv /opt/psa/admin/plib/modules/nextcloud/library/Releases.php /opt/psa/admin/plib/modules/nextcloud/library/Releases.php.back

5. Put the hotfix instead:

   # mv Releases.php /opt/psa/admin/plib/modules/nextcloud/library/

6. Once Nextcloud notifies that the last version was uploaded again, move the original file back.