Issue Summary

When an add-on is deleted from the Market place , "Manage subscription" page under admin.atlassian.com will not load. Instead it throws a generic error message that "We cant load this page right now".

Steps to Reproduce

1. Add-on is deleted from marketplace by the vendor, which in this case is ZAPI cloud which is deleted from Marketplace at the time of this ticket creation.
2. Access the "Manage subscription" page.

Expected Results

Page should load with other subscription details, possibly with a warning that ZAPI ( add-on in question) is deleted by vendor.

Actual Results

Manage subscription page loads with generic error message.

The below exception is thrown in network tab

Request - {cloud_id}/bill-estimate
Response - 500 Error. {"message":"Request failed with status code 400"}

Workaround

Currently there is no known workaround from the UI, as we cannot un-subscribe the add-on from the "Manage Apps" section. ( Please refer screen shot).
Please do reach out to https://support.atlassian.com with this Bug details to get it un-subscribed from the back end.