Rotate Region causing crash

[micheus]

Just by selecting a face and applying Rotate->Region I'm getting a crash:

Code:

Internal Error
Version: 2.1.5.42.ga564
Window: geom
Reason: badarith

Stack trace:
[{e3d_mat,rotate,2,[{file,"f:/unixlike/src/wings/e3d/e3d_mat.erl"},{line,98}]},
{wpc_region,rotate,5,
             [{file,"f:/unixlike/src/wings/plugins_src/commands/wpc_region.erl"},
              {line,156}]},
{lists,foldl,3,[{file,"lists.erl"},{line,1263}]},
{wings_drag,motion_update_fun,2,
             [{file,"f:/unixlike/src/wings/src/wings_drag.erl"},{line,1288}]},
{wings_dl,map_1,5,
           [{file,"f:/unixlike/src/wings/src/wings_dl.erl"},{line,268}]},
{wings_drag,motion_update,2,
             [{file,"f:/unixlike/src/wings/src/wings_drag.erl"},{line,1270}]},
{wings_drag,handle_drag_event_2,2,
             [{file,"f:/unixlike/src/wings/src/wings_drag.erl"},{line,741}]},
{wings_drag,do_drag,2,
             [{file,"f:/unixlike/src/wings/src/wings_drag.erl"},{line,471}]},
{wings_wm,handle_event,3,
           [{file,"f:/unixlike/src/wings/src/wings_wm.erl"},{line,952}]},
{wings_wm,send_event,2,
           [{file,"f:/unixlike/src/wings/src/wings_wm.erl"},{line,918}]},
{wings_wm,do_dispatch,2,
           [{file,"f:/unixlike/src/wings/src/wings_wm.erl"},{line,824}]},
{wings_wm,dispatch_event,1,[{file,[...]},{line,...}]},
{wings_wm,get_and_dispatch,0,[{file,...},{...}]},
{wings,init,1,[{...}|...]}]