Normalize Sizes crash dump

[Hank]

Hello all W3D users,

Currently I'm working with quite complicated object and now when I want to UV map it I got W3D crash dump like this:

Dump written 2016-9-5_21-7
Version: 1.5.4
Window: {autouv,4}
Reason: badarith

Short stack trace:
[]

Long stack trace:
[{wpc_autouv,'-handle_command_1/2-fun-4-',3,
[{file,"wpc_autouv.erl"},{line,874}]},
{lists,foldl,3,[{file,"lists.erl"},{line,1262}]},
{wpc_autouv,handle_command_1,2,[{file,"wpc_autouv.erl"},{line,883}]},
{wpc_autouv,handle_command,2,[{file,"wpc_autouv.erl"},{line,830}]},
{wings_wm,handle_event,3,[{file,"wings_wm.erl"},{line,825}]},
{wings_wm,send_event,2,[{file,"wings_wm.erl"},{line,797}]},
{wings_wm,do_dispatch,2,[{file,"wings_wm.erl"},{line,698}]},
{wings_wm,get_and_dispatch,0,[{file,"wings_wm.erl"},{line,612}]}]

All objects are combined to one and separately had UV mapping. When I select whole object and go to scale -> normalize sizes the error shows up.

What cause it?
Did I miss some UV or some vertices are too close each other?

could you analyse it with attached crash dump?

BR, Hank