Compressed banks are simply .zip folders that the synth should be able to read.
They are marked with a "lock" symbol, since they are read-only.
However, on some systems it seems that the synth is unable to read filenames from those archives, hence making it difficult to see and load the patches. The rightmost window that should list all the patches, simply shows up empty.
This is likely a bug!

Now, if you have this issue, I would be interested in any system info you can provide, like DAW / OS version, install path, etc., so this issue can be fixed.
Thanks.
