Problem

Unable to install app by uploading jar file.

Error returned:

Solution 1 - Install using app URL from marketplace

1. Go to app listing on the Atlassian marketplace

2. Retrieve app URL

   Open

   

    

3. Paste the app URL and click on Upload

   Open

   

Solution 2 - Install app manually

1. Download the jar file from Atlassian marketplace

2. Shut down Jira instance

3. Copy the JAR file (e.g., AttachmentChecker-5.9.0.jar) into your JIRA home directory under plugins/installed-plugins/

4. Start JIRA

5. Confirm the installation by going to Administration > Manage Add-ons. Attachment Checker should appear in the list as enabled.

Root Cause

The .jar file size is too big.