Thanks for the quick heads up. We released a new version (1.71) which will hopefully mitigate your issue.

Your issue likely applies to any add-on you are trying to install on Mozilla Focus since it does not support installing add-ons from the browser, which makes sense since Focus is a product whose primary purpose is to ensure the highest data privacy and security: allowing any add-on created by random people would be a massive potential for data breach and hacking. Most people use Firefox Desktop or Firefox for Android, and add-ons work fine there. There has been a recent upgrade from Mozilla that might allow you to install the .xpi though: https://bugzilla.mozilla.org/show_bug.cgi?id=1814123. Feel free to open an issue in our Github repo if you'd like to discuss more, but again, we never claimed that this add-on would work on a Firefox product that isn't suited for add-ons.

Hi, it would be nice of you to share some more info, such as the type of issue, the browser version and if it happens only in specific cases. Perhaps you can add those details by editing your post above? Thanks.