Regarding filed bug: https://bugs.adobe.com/jira/browse/FM-1141
It is reproducible - if you change the logger from default, you lose error messages silently. Adobe agrees with that in the bug, and the patch is in there. But right now not scheduled to be included in OSMF 1.6.
Can I get some assistance from the forum?
I would like Adobe to apply the patches that are in the bug as suggested workarround.
The bug was deferred for the 1.5 release (which is now available), it will be considered for the next release.