Theme editor does not open style.css

Hi, I am building a new theme for Bootjesgek.nl and I would like to use the WordPress build-in theme editor. I am building in a home server so I can’t give you any links. All files of the theme open in the editor, but not style.css. I wonder what might be the cause. I also tried the Advanced editor plug-in and the WP editor plug-in.
In other editors like Komodo and NotePad++ the file opens normally.
When I remove the introduction text, the file does open so there is a clue; but I Would like to keep the introduction. What could I change there to make this work? Here is the file:

/*
Theme Name: Bootjesgek 2.0
Theme URI:
Description: Basic Magazine three column theme, sidebars on the right.
Version: 0.1
Author: McCage; based on Theme Dreamer Basic 303.
Author URI: Bootjesgek.nl
*/

/*---------------------------------------------------------------------------------

[Table of contents]

1. Initial Styling - General tags, the background, global attributes (overridden by following regions).
2. Header Region - Styles specific to header region, title, slug, top menu, etc.
3. Content Region - Styles for content appearance, blockquotes, posts, pages, wp-caption, etc.
4. Comments Region – Styles for comment thread, forms, etc.
5. Sidebar Region – Styles for widgets, additional menus lists and links.
6. Footer Region – Styles specific to the footer region.
7. Misc. & Plugins – Miscellaneous, override plugins, define last rule, fix anomalies, etc.

-----------------------------------------------------------------------------------*/
/*=== START SECTION 1 - Initial Styling ===*/
body {
	font-family:  Arial, sans-serif;
	font-size: 85%;
	margin: 0px;
	padding: 0px;
	color: #555555;
}
#wrapper {
	width: 1000px;
	margin: 12px auto 20px auto;
	padding: 0px;
}
.alignleft {
  float: left;
}
.alignright {
  float: right;
}
img.aligncenter, div.aligncenter {
	display: block;
	margin: 0 auto;
}
img.alignright, div.alignright {
	margin: 1px 0 2px 10px;
	display: inline;
}
img.alignleft, div.alignleft {
	margin: 1px 10px 2px 0;
	display: inline;
}
/*=== END SECTION 1 - Initial Styling ===*/

/*=== START SECTION 2 - Header Region ===*/
#header {
	height: 130px;
	width: 1000px;
	margin: 0px;
}
#header h1 a:link, #header h1 a:visited {
	text-decoration: none;
	font-size: 1em;
	float: left;
	font-family: Georgia, "Times New Roman", Times, serif;
	margin: 0px;
	width: 600px;
	padding: 1px 0 0 25px;
	clear: both;
}
#header h1 a:hover {
	text-decoration: underline;
}
.description {
	clear: left;
	padding: 5px 0 5px 35px;
}
#menu{
	padding: 0;
	white-space: nowrap;
	margin: 20px 0 0 0;
	width: 1000px;
}
#menu ul {
	margin: 0px;
	padding: 0px;
}
#menu li {
	display: inline;
	list-style-type: none;
	margin: 0 10px 0 0;
}
#menu li a:link, #menu li a:visited {
	padding: 3px;
	text-decoration: none;
}
#menu li a:hover {
	text-decoration: underline;
}
/*=== END SECTION 2 - Header Region ===*/

/*=== START SECTION 3 - Content Region ===*/
#main {
	width: 1000px;
}
#content {
	width: 480px;
	padding: 10px;
	float: left;
	line-height: 1.3em;
}
#content a:link, #content a:visited {
	text-decoration: none;
	padding: 2px;
}
#content a:hover {
	text-decoration: underline;
}
#content h1 {
	font-size: 1.5em;
}
.wp-caption {
	border: 1px solid #ddd;
	text-align: center;
	background-color: #f3f3f3;
	padding-top: 4px;
	margin: 10px;}.wp-caption img {
	margin: 0;
	padding: 0;
	border: 0 none;
}
.wp-caption p.wp-caption-text {
	font-size: 11px;
	line-height: 17px;
	padding: 0 4px 5px;
	margin: 0;
}
.post {
	padding: 5px;
	font-size: .9em;
}
.post h2 {
	font-size: 1.8em;
	margin: 45px 0 10px 0;
	padding: 0;
}
.post h3 {
  font-size: 1.8em;
  margin: 0;
  padding: 0;
}
.post-edit-link img{
	border: none;
}
a.post-edit-link:link, a.post-edit-link:visited {
	text-decoration: none;
}
.entry-content, .entry-excerpt {
	clear: left;
}
.entry-content blockquote {
  font: 1.2em/1.5em Georgia, "Times New Roman", Times, serif;
  color: #000000;
  width: 345px;
  background: url(images/blockquote1.png) no-repeat right bottom;
  padding: 0 0 0 30px;
  text-indent: -15px;
}
.entry-content blockquote p {
  background: url(images/blockquote2.png) no-repeat left top;
  padding: 0 0 0 60px;
  font: italic 1.5em Georgia, "Times New Roman", Times, serif;
}
a.image:link, a.image:visited, a.image:hover {
	background: none;
	padding: 0;
}
a.image img {
	border: none;
}
.entry-date {
	height: 89px;
	width: 71px;
	display: inline;
	float: left;
	margin: 0 10px 0 0;
	border: 2px solid #000000;
	color: #000000;
	font-family: Georgia, "Times New Roman", Times, serif;
}
.entry-month {
	font-size: 19px;
	width: 71px;
	text-align: center;
	height: 28px;
	margin: 7px 0 0 0;
	font-weight: bold;
	padding: 0 0 2px 0;
}
.entry-day {
	font-size: 28px;
	text-align: center;
	height: 30px;
	width: 71px;
	margin: 4px 0 0 0;
	font-weight: bold;
	line-height: 30px;
}
.navigation {
  clear: both;
}
.entry-meta {
  margin: 0 0 10px 0;
}
.underpost {
	font-size: .9em;
}
.underpost a {
	text-decoration: underline;
}
/*=== END SECTION 3 - Content Region ===*/

/*=== START SECTION 4 - Comment Region ===*/
.avatar {
  float: right;
  margin: 0 0 3px 5px;
}
#respond p {
	font-size: 0.9em;
}
#respond label {
	display: block;
	margin: 5px 0 5px 0;
}
#comment {
	width: 100%;
}
.thread-even {
	background-color:#F9F9F9;
}
.thread-odd {
	background-color:#E5E5E5;
}
#commentform {
	padding: 10px;
}
ol.commentlist {
	list-style-type: none;
	margin: 0px;
	padding: 0px;
}
ol.commentlist li {
	margin: 15px 0 0 0;
}
ol.commentlist li a {
	text-decoration: underline;
}
/*=== END SECTION 4 - Comment Region ===*/

/*=== START SECTION 5 - Sidebar Region ===*/
#sidebar-right {
	width: 245px;
	float: right;
	margin-top: 10px;
}
#sidebar-left {
	width: 245px;
	float: left;
	margin-top: 10px;
}
#sidebar-left h1, #sidebar-right h1 {
	font-size: 1.4em;
}
#sidebar-left h2, #sidebar-right h2 {
	font-size: 1.1em;
}
#sidebar-left li a:link, #sidebar-left li a:visited, #sidebar-right li a:link, #sidebar-right li a:visited {
	display: block;
	text-decoration: none;
	margin-bottom: 0.1em;
	padding: 1px;
}
#sidebar-left li a:hover, #sidebar-right li a:hover {
	background-color: #FFFFFF;
}
#sidebar-left ul, #sidebar-right ul {
	margin: 0px;
	padding: 0px;
	list-style-type: none;
}
#sidebar-left ul ul, #sidebar-right ul ul {
  margin-left: 10px;
}
#sidebar-left ul ul li, #sidebar-right ul ul li {
  font-size: .9em;
  margin-left: 10px;
}
/*=== END SECTION 5 - Sidebar Region ===*/

/*=== START SECTION 6 - Footer Region ===*/
#footer {
	height: 42px;
	clear: both;
	text-align: center;
	font-size: 0.8em;
	padding: 13px 0 0 0;
}
#footer a:link, #footer a:visited {
	color: #474200;
}
#footer a:hover {
	text-decoration: none;
}
/*=== END SECTION 6 - Footer Region ===*/

/*=== START SECTION 7 - Misc. & Plugins ===*/
/* insert your misc. styling here. */
/*=== END SECTION 7 - Misc. & Plugins ===*/