Salesforce Mentions does not load and produces error due to insufficient permissions

Summary

When Mentions is clicked, a pop-up menu produces an error instead of showing every Salesforce Object on a Confluence page:

Environment

Confluence or JIRA version
Add-on version

Diagnostics Steps

Not applicable.

Cause

There are two possible causes of this issue:

Salesforce & Confluence Cloud Connector (addon_com.servicerocket.confluence.salesforce) user does not have permission on the space where the page with Salesforce macro exists
The page that has Salesforce macro is restricted from Salesforce & Confluence Cloud Connector (addon_com.servicerocket.confluence.salesforce) user

When you install this add-on, it automatically creates a user with the name Salesforce & Confluence Cloud Connector (addon_com.servicerocket.confluence.salesforce). This user is then automatically added to the space permission where the Salesforce macro is in use and should not be removed to prevent denied access which could cause this problem.

Workaround

Give Salesforce & Confluence Cloud Connector (addon_com.servicerocket.confluence.salesforce) user the appropriate permission on space and page level.

Resolution

Not applicable.