If you attempt to save a draw.io diagram in JIRA Cloud and receive the message "Error saving file. Insufficient access rights.", there is a problem with up to 3 permissions in your JIRA setup.
Note: We will refer to a BASE_URL prefix below. If your JIRA instance is at, for example, https://test.atlassian.net, that is your BASE_URL. You need to replace this wherever you see "BASE_URL". You will need admin permissions to make the required updates.
To write a new draw.io diagram you require the permission "create attachments".
To update your own existing diagram you require the permissions "delete own attachments" and "create attachments".
To update someone else's existing diagram you require the permissions "delete all attachments" and "create attachments".
JIRA doesn't have an "update" command, attachments have to be deleted then created again.
Navigate to BASE_URL//secure/project/ViewProjects.jspa. There, click on the project name. Then, in the project settings click on "Permissions". Scroll down and find the section entitled "Attachment permissions"
To ensure users can operate draw.io without encountering this problem it is best to allow any logged in user these permissions. About is shown the default software scheme in JIRA 7.1. Delete All Attachments isn't available to all users, so updates to other users' diagrams will fail. One route is to edit the permission scheme and for "Delete All Attachments" add "Application access" - "Any logged in user".
Another solution is to create a Project Role called "drawio" and add that project role to all three permissions. Then you can add users you to that project role. It is important you use "drawio", since in the future we will check for that role and restrict application usage to only these users.