When you install an add-on, JIRA will automatically grant the add-on the correct permissions for its scope through the atlassian-addons-project-access role. It will also check the permissions of existing add-ons across all JIRA and JIRA Service Desk projects and grant them the correct permissions as well.
If you're experiencing issues attaching or removing files or folders to Jira issues using Team Files, please verify if you have the correct Issues Permissions Schema for the Project Role: atlassian-addons-project-access.
<your-jira-instance-url>/jira/settings/issues/permission-schemes
For more details about atlassian-addons-project-access on Jira configuration click here.
Note
If you’re still unable to use or install the app correctly after having this permission set, that should be a problem with the atlassian-addons-admin group. To fix that, you will need to contact Atlassian support. For more information about this topic please check the community here and the open Jira issue here.