1. AddOn Installation and Reinstallation

With the respect of the JIRA Cloud architecture, we have to host our AddOn in a separated server machine. The access of JIRA is done via REST APIs.  The registration of the AddOn in our server is done during the AddOn Installation. If you meet a generic problem to access our server, it could be a problem of AddOn Registration. You need to re-install it. here is the steps of re-installation:

• Disable the AddOn
• Unsubscribe
• Uninstall
• Install again

If you meet a problem on this matter, please contact directly the support of Atlasssian. 

2. JIRA Setting

2.1. Global Permission configuration

There is a known bug in JIRA Cloud with any AddOn to get the user permission. You need make the following modification to setup the global permission in order that our AddOn works correctly.

1. Log as Administrator
2. Go to the System of JIRA
   
3. Click on the Global Permission
   
4. Go to the bottom of this page and Add the "Browse user" permission to the group "atlassian-addons-admin" 
   

2.2. Screen Configuration

Our AddOn uses the JIRA REST APIS to retrieve all information of JIRA. We have noticed that the accessibility of JIRA issues is controlled by not only by JIRA permission, but also JIRA Screen Scheme setup in each project. If a field is not present in project screen, we'll get an exception when we access the value. Here is en example, when we change the duration: 

There are three kinds of screens for issue creation, issue edition and issue view.

The following fields are used by our AddOn,

Assignee, Component/s, Due Date, DueTime, Fix Version/s, PercentDone, Time Tracking and Reporter.

they must be present in all screens.