See https://bugzilla.mozilla.org/show_bug.cgi?id=1511726
Assuming you're on non-Windows, the message is expected and not indicative of a problem. I've pushed a patch to disable it going forward. Sorry for the noise.
Assuming you're on non-Windows, the message is expected and not indicative of a problem. I've pushed a patch to disable it going forward. Sorry for the noise.