I have several files that when they are saved they will not open back up.
when I open a working file it is a "pk /Zip" Compressed file.

EX: 
PK     ! K      [Content_Types].xml (UN0#q)!ԔC# `mcձ-ﶴ& (TK&Φ1\66B]X?.uLdH傇B, `X(KJa"x~2 RXF'j J<bп:ʮ|{zTP1:P9I'FV zZ1t12XP,3{ PAN@vݨI`{sD4`5ׄH ؚ}K'&p]id,m
ok that is fine.. it works... but after working and saving several times it saves and it no longer works.. and this is what it shows in txt viewer.

EX: 
{\rtf1\adeflang1025\ansi\ansicpg1250\uc1\adeff37\deff0\stshfdbch11\stshfloch0\stshfhich0\stshfbi0\deflang1045\deflangfe1045{\fonttbl{\f0\froman\fcharset238\fprq2{\*\panose 02020603050405020304}Times New Roman{\*\falt Times};}{\f2\fmodern\fcharset238\fprq1{\*\panose 02070309020205020404}Courier New{\*\falt Arial};}{\f3\froman\fcharset2\fprq2{\*\panose 05050102010706020507}Symbol{\*\falt Times};}{\f10\fnil\fcharset2\fprq2{\*\panose 05000000000000000000}Wingdings{\*\falt Symbol};}{\f11\froman\fcharset128\fprq1{\*\panose 02020609040205080304}MS Mincho{\*\falt Arial Unicode MS};
looks like an old rtf file, but it doesn't open as that either. I have not made any changes in my saving practices. I save the same way each time. It is random. out of 30 files this will happen 5-10 times I have NO ideas how to keep this from happening.