MyWarcraftStudio Stops working

[astralis]

As mentioned above, i have some problems with MyWarcraftStudio. I started Modelchanging today, and this is the order of how i do it:

1. I locate the file i want to transfer my old item with in WarcraftStudio

2. Extract it and rename it to the old one

3. Open MPQeditor, locate the old file, delete it (and backup if i want to) then "Add file(s)" and put in the new renamed file.

Now here lies the problem. In my World of Warcraft\Data folder, there are 3 different MPQ files: common.mpq, patch.mpq and expansion.mpq.

They all contain different files and models depending on what i need, but the problem is, that if i deleted old file + added new in, say, common.mpq... Then it works good in-game, but when i then later attempt to open the common.mpq file in MyWarcraftStudio it refuses to load/open, like it simply ignores it, while patch.mpq and expansion.mpq keeps working perfectly.

So in short: After a mpq archieve has been edited through MPQeditor it refuses to open in MyWarcraftStudio.. Help would be mostly appreciated.. Hoping for reply <3