How to fix Confluence Workbox issue

Problem

The Excellentable v4.2.1.1 or v4.2.1 plugin causes the Confluence workbox to throw an error. The exception mentioned in the stack trace is IllegalArgumentException: Malformed \uxxxx encoding.

Expectation - Excellentable should not cause any cascading failures.

Symptoms

An error message appears instead of notifications in Confluence workbox screen, as shown below:

Steps to reproduce the issue

1. Install OOTB Confluence 7.4.0
2. Install Addon Excellentable v4.2.1.1 or v4.2.1 
3. Create a page then add the Excellentable macro
4. @mention users in the page or any actions that triage the workbox notification
5. Click the workbox ( the notifications icon at the top of the page)

The  Atlassian Knowledge Base article was created by Atlassian explaining the impact of the issue.

Recommendation & resolution for customers

• Install Excellentable v4.2.1.2, released on 20 May 2020 , in which Addteq addressed and fixed the workbox issue.