Dunno if anybody else have this problem but I tried to comment the XML/tag.sublime-snippet (putting a <!-- at the beginning and a --> at the end)
What I have done if you want to redo the problem :
I opened the file : %USERDATA%/Application Data\Sublime Text\Packages\XML\tag.sublime-snippet
I dded a "<!--" at the beginning and a "-->" at the end of the file (without the ")
When I saved the snippet, sublime crashed
I tried to reload it, it crashed again.
I opened the same in a different editor and I remove the XML comments. I opened again sublime and no problem to open it.
Maybe a problem if the snippet is only a comment ?