The message port closed before a response was received

[rudiedirkx]

Sometimes in the page's devtools console:

[RWeb] WILL START AUTO-DOWNLOAD NOW! See background script for log.
Unchecked runtime.lastError: The message port closed before a response was received.

Is that the fault of

rweb.browser.runtime.sendMessage({forceAutoDownload: true}, function(response) {

and beyond? The download does happen, and is registered in the log. It just can't communicate back to the page?? Because the page was sleeping, or because the extension's SW was sleeping?