Can't save or export after welding

[dako64]

After welding to remove a hole, an internal error will prevent me from saving or exporting a model. It also deletes the wings file I am working on leaving me only with an autosave (wings~) file. Repeated the process a few times to make sure it was the welding. I was able to delete the hole without the tool, but could still could not save.

Dump written 2014-3-12_22-11
Version: 1.5.2
Window: geom
Reason: function_clause

Short stack trace:
[]
Long stack trace:
[{gb_trees,get_1,[-1,nil],[{file,"gb_trees.erl"},{line,245}]},
{wings_we,'-do_renumber/3-lc$^0/1-0-',2,[{file,"wings_we.erl"},{line,677}]},
{wings_we,do_renumber,3,[{file,"wings_we.erl"},{line,677}]},
{wings_we,renumber,3,[{file,"wings_we.erl"},{line,268}]},
{wings_ff_wings,renumber,5,[{file,"wings_ff_wings.erl"},{line,674}]},
{wings_ff_wings,export,2,[{file,"wings_ff_wings.erl"},{line,616}]},
{wings_file,save_now,2,[{file,"wings_file.erl"},{line,409}]},
{wings_develop,time_command,2,[{file,"wings_develop.erl"},{line,81}]}]