".indexName not valid" after removing 3rd party calendar

[phodo]

"Find New Apps" does not load and has a warning: ".indexName" not valid. My Jira Calendar is missing from Top Menu: "Apps" in Jira.

A possible cause?

I am using the Jira Calendar and have fully integrated my calendars. While figuring out my needs I installed "Calendar for Jira" by "Do it Better". I did not used and promptly removed

I un-subscribed to the app while still in the trail.

[Angélica Luz]

Hello @phodo,

Welcome to Atlassian Community!

Searching for similar cases related to this error, I didn’t find anything with this exact same message. 

I would like to know if you cleared your browser cache and cookies and also if you tested using another browser.

Is this issue affecting other users on your site?

If possible, share a screenshot of the error with us (just make sure to hide private information).

Also, open the developer tools on your browser and check on the console tab if it shows any other error related to the Jira Calendar add-on.

Kind regards,
Angélica