Summary

While navigating to "Manage Apps" page via below 2 options, "Page not found" exception is seen.

1. ⚙️ > Manage apps 
2. Directly via the URL : "https://{bamboo-url}/plugins/servlet/upm"

Environment

Issue seen on Bamboo 8.2.1. 

Diagnosis

• Try to visit the "Manage Apps" page via the options described under the summary section, "Page not found" exception will be seen.
  
  
• Also while navigating to ⚙️ > Overview > Manage Apps section, "Find new apps" and "Manage apps" sections are missing, please refer below.

Cause

• The first cause is Incompatible Universal Plugin Manager (UPM) Installed on the Bamboo Instance.
• The second is on the DB side , UPM is in a disabled state. 

Solution

Solution 1 for Incompatible versions on the server : 

• By default Bamboo ships a default supported version of UPM which is present in <bamboo-install>/atlassian-bamboo/WEB-INF/atlassian-bundled-plugin as atlassian-universal-plugin-manager-plugin-x.x.x.jar

          The version of the jar may vary based on the version of Bamboo, for 8.2.1 supported jar version is atlassian-universal-plugin-manager-plugin-4.3.4.jar

• The first step is to look for <bamboo-install> and <bamboo-home> folder to find if there are any incompatible Jar's present especially in below folders. If any atlassian-universal-plugin-manager-plugin-x.x.x.jar is found, please take a backup of the jar's and delete the jar's from these folders. Following command can be used to run the search.

find . -name "*atlassian-universal-plugin-manager-plugin*"

1. <bamboo-home>temp
2. <bamboo-home>caches
3. <bamboo-home>shared/plugins
4. <bamboo-install>temp          

• Please restart Bamboo and see if the manage App's page is visible or not.

Solution 2 for Disable plugin state on DB : 

• If the Issue still exists, please run the below query in the Database.

select * from bandana where bandana_key like 'bamboo.plugin.state'

• The below entry should be marked as true from the results above. 

<string>com.atlassian.upm.atlassian-universal-plugin-manager-plugin</string> <boolean>true</boolean>

• Please restart Bamboo post doing the changes on the DB side.
• The Issue should be resolved now.