ZBrushCentral

unwrapping for too long

hello,
Does anyone knows what does it mean when unwrapping takes too long? (for ex: polygroups 1/1 cut handeling 1015/9 and so on… )
Why does it happen ? how can it be fixed? should it be fixed?
thank you…

Any time I get that message, it’s down to a problem with the mesh which causes UV Master to hang forever.