A bit of an odd one.
I'm using Excel for crunching some data I have in several .txt files.

When I'm trying to import them via `Data` > `Get External Data` > `Import Text File`:

![Excel Import Text File](https://i.stack.imgur.com/5iRsU.jpg)

Like as I've done many times in the past, I get the "Choose a File" Dialog Box, but when I browse to the folder, only a couple of the files are "selectable"; the others are "Grayed out":

![**SOME** Source Files Grayed Out](https://i.stack.imgur.com/qqJCr.jpg)

There are no differences between the files that I can see that would justify the difference. The only "logic" is that the "source" file (let's call it `20150728 - SOURCE.TXT`) comes via email from a Windows machine, and the two other locked files (`20150728 - Source Fragment 3.TXT` and `20150728 - Source Fragment 3 copy.TXT`) are a *copy* of the Source where I've deleted some lines, and a second copy of the resulting file, while the non-locked ones started out as the Source where I deleted lines, and then did a "Save As" in TextWrangler...

I *can* work around the issue just by copying the contents of the "grayed" files into a new document in TextWrangler and saving it, but I'd like to understand the reason for this behavior.

Doing a `file` in the files in question shows them to be similar if not the same:

```
Mac:samples jjarava$ file 201507*txt
20150728 - Source Fragment 3.TXT:      ASCII text
20150728 - Source Framgent 1.TXT:      ASCII text
20150728 - Source Fragment 1.TXT:      ASCII text
20150728 - Source.TXT:                 ASCII text, with CRLF line terminators
20150728 - Source Fragment 3 copy.TXT: ASCII text

```

I'm a bit "stuck" on what the issue might be. I have the feeling it's one of those "Obscure Mac Quirks" that are very hard to explain.

**EDIT**: As per the comments below from @user3439894 and others, I've looked into the extended attributes of the files to see if that yields any hint.

The output of `ls -l@`for the files gives us:

```
-rw-r--r--@ 1 jjarava  staff   7652 Aug  3 13:58 20150728 - Source Fragment 3 (BAD).TXT
    com.apple.FinderInfo       32 
    com.apple.TextEncoding     15 
    com.dropbox.attributes     83 
-rw-r--r--@ 1 jjarava  staff   6570 Aug  3 13:58 20150728 - Source Fragment 1 (Good).TXT
    com.apple.FinderInfo       32 
    com.apple.TextEncoding     15 
    com.dropbox.attributes     83 
-rw-r--r--@ 1 jjarava  staff   6616 Aug  3 13:58 20150728 - Source Fragment 2 (Good).TXT
    com.apple.FinderInfo       32 
    com.apple.TextEncoding     15 
    com.dropbox.attributes     83 
-rw-r--r--@ 1 jjarava  staff  21138 Aug  3 13:58 20150728 - Source (BAD).TXT
    com.apple.FinderInfo       32 
    com.dropbox.attributes     83 

```

Again, I see that one of the *bad* files (Source) is apparently missing the `com.apple.TextEncoding` attribute -- but the other "not working" file *does* have the attribute... Just in case the values are different for the good and bad files, let's check:

```
Mac:samples jjarava$ xattr -p com.apple.TextEncoding 201507*txt
20150728 - Source Fragment 3 (BAD).TXT: UTF-8;134217984
Source Fragment 1 (Good).TXT: UTF-8;134217984
Source Fragment 2 (Good).TXT: UTF-8;134217984
xattr: 20150728 - Source (BAD).TXT: No such xattr: com.apple.TextEncoding

```

So that doesn't seem to be the trick either...