When using "Remove tags from file(s)" on FLAC files, WAVEFORMATEXTENSIBLE_CHANNEL_MASK is also removed. So, files with non-standard channels layout (and even some standard layouts - 6.1, for example) cannot be decoded correctly after this. This seems like undesirable behavior.
Also fb2k decodes 7-channel FLAC without WAVEFORMATEXTENSIBLE_CHANNEL_MASK as FL-FR-FC-LFE-RL-RR-FCL, but according to Vorbis standard channel mapping it should be decoded as FR-FL-FC-LFE-RC-SL-SR - https://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-810004.3.9
the stream is 6.1 surround. channel order: front left, center, front right, side left, side right, rear center, LFE
Actually, default decoding 7-channels as FL-FR-FC-LFE-RL-RR-FCL has no meaning at all, because there is no standard layout like this in any format.
Don't know if it always worked this way. I tested only 1.6.2 and 1.6.6 beta 6.
Why do you link to Vorbis specs if you talk about FLAC? Vorbis uses odd channel orders that aren't used anywhere else. FLAC has its own specs, check https://xiph.org/flac/format.html#frame_header (https://xiph.org/flac/format.html#frame_header).
Thanks for correction. But in FLAC specification we can see that 7-channel is "front left, front right, front center, LFE, back center, side left, side right", so not FL-FR-FC-LFE-RL-RR-FCL anyway
Good find, thanks for reporting.
Removal of tags should not alter decoding output, this will be addressed in a future update.
Fixed in beta 7.