Unchecked lastError value: Error: Could not establish connection. Receiving end does not exist.

[bertvandepoel]

While debugging an unrelated Firefox addon I'm developing, I noticed the addon/WebExtension debugging console also displayed an error for the mooltipass addon. From time to time, a new error identical to the following is thrown:

Unchecked lastError value: Error: Could not establish connection. Receiving end does not exist. event.js:15
messaging moz-extension://241d6607-988e-4dff-9a96-cdd0aa9137be/background/event.js:15

While the addon seems to work fine, I use it all the time, it might be relevant to look into regardless. If you're unable to replicate this problem, feel free to ask me to investigate further.