Title: Error adding Stylesheet. Invalid file format.
Last modified: August 20, 2016

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# Error adding Stylesheet. Invalid file format.

 *  Resolved [leejosepho](https://wordpress.org/support/users/leejosepho/)
 * (@leejosepho)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/error-adding-stylesheet-invalid-file-format/)
 * I have a Twenty Twelve Child Theme in 3.5. I activated the plugin on one of my
   sites and received this error:
 * `Error adding Stylesheet. Invalid file format.`
 * What can I do to try to correct that?
 * Many thanks.
 * [http://www.nonameyet.org/](http://www.nonameyet.org/) – [http://www.nnywriters.com/](http://www.nnywriters.com/)
 * PS: I had only tried the plugin on one of my sites and I see some encouraging
   improvement in spite of the error!
 * [http://wordpress.org/extend/plugins/ie-css3-support/](http://wordpress.org/extend/plugins/ie-css3-support/)

Viewing 3 replies - 1 through 3 (of 3 total)

 *  Thread Starter [leejosepho](https://wordpress.org/support/users/leejosepho/)
 * (@leejosepho)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/error-adding-stylesheet-invalid-file-format/#post-3347928)
 * Update: The error there was mine, not the plugin’s. I do not yet understand and
   know how to use the plugin completely, and the plugin has already made a great
   improvement. I now get my rounded corners in IE8, but I do not get my blue outline
   around the pages.
 * Can you help with that?
 * Also, maybe you would have some thoughts related to things in my latest post 
   here:
    [http://wordpress.org/support/topic/does-bps-possibly-do-anything-like-headerx-ua-compatible-ie7?replies=28#post-3710355](http://wordpress.org/support/topic/does-bps-possibly-do-anything-like-headerx-ua-compatible-ie7?replies=28#post-3710355)
 * Many thanks!
 *  Plugin Author [Cristopher Dino](https://wordpress.org/support/users/cristopher-dino/)
 * (@cristopher-dino)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/error-adding-stylesheet-invalid-file-format/#post-3348082)
 * Hi Leejosepho,
 * Thank you for using my plugin. I’m Cristopher, The developer of the plugin. Sorry
   for the late reply.
 * I think the border problem is not in the plugin. I have checked your CSS code(
   [http://www.nnywriters.com/wp-content/themes/ChapterTwelve/style.css](http://www.nnywriters.com/wp-content/themes/ChapterTwelve/style.css)).
   I found out that your border( border: 8px solid #69c ) is under a media query
   condition( [@media](https://wordpress.org/support/users/media/) screen and (min-
   width: 960px) { ). IE do not support media query condition. I suggest you put
   the code( border: 8px solid #69c; ) outside the condition( [@media](https://wordpress.org/support/users/media/)
   screen and (min-width: 960px) { ).
 * Your code must look like this:
 *     ```
       body .site {
               border: 8px solid #69c;
       }
       @media screen and (min-width: 960px) {
       	body {
       		background-color: #e6e6e6; /* light gray: http://www.colorhexa.com/e6e6e6 */
       	}
       	body .site { /* added for certain browsers */
       		padding: 0 24px; /* 40px; */
       		padding: 0 1.714285714rem; /* 2.857142857rem; */
       		margin-top: 24px; /* 48px; */
       		margin-top: 1.714285714rem; /* 3.428571429rem; */
       		margin-bottom: 24px; /* 48px; */
       		margin-bottom: 1.714285714rem; /* 3.428571429rem; */
       		-moz-border-radius: 20px;
       		-webkit-border-radius: 20px;
       		-khtml-border-radius: 20px;
       		border-radius: 20px;
       		box-shadow: 0 2px 6px rgba(100, 100, 100, 0.3); /* very dark: http://www.netgfx.com/RGBaZR/ */
       		max-width: 100%; /* added to attain full-width */
       	}
       ```
   
 * Give it a try! let me know if it worked for you.
    Also, If you liked the plugin,
   I’ll appreciate if you could give it a rate here:
 *  Thread Starter [leejosepho](https://wordpress.org/support/users/leejosepho/)
 * (@leejosepho)
 * [13 years, 4 months ago](https://wordpress.org/support/topic/error-adding-stylesheet-invalid-file-format/#post-3348083)
 * > Give it a try! let me know if it worked for you.
 * Perfectly, and I hardly know how to thank you! Being a rookie at all of this,
   I had no idea I only needed to move one line of code.
 * Many thanks.
 * > Also, If you liked the plugin, I’ll appreciate if you could give it a rate…
 * Certainly, and I commend your fine work in making my Twenty Twelve “mobile-first”
   Theme work so very well in IE.

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘Error adding Stylesheet. Invalid file format.’ is closed to new replies.

 * ![](https://s.w.org/plugins/geopattern-icon/ie-css3-support_f8e8db.svg)
 * [IE CSS3 Support](https://wordpress.org/plugins/ie-css3-support/)
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 * 3 replies
 * 2 participants
 * Last reply from: [leejosepho](https://wordpress.org/support/users/leejosepho/)
 * Last activity: [13 years, 4 months ago](https://wordpress.org/support/topic/error-adding-stylesheet-invalid-file-format/#post-3348083)
 * Status: resolved