RadStyleSheetManager breaks page
I have dropped a stylesheetmanager control onto my master page, just within the form tag, like so:
Yes, there are some issues with the RadStyleSheetMananger and we logged an issue about it - ID#109945 which was also reported by you.
the Telerik team
The bug I reported was that the RadStyleSheetManager broke the page when an empty Style Sheet Manager was added to the page. Are you essentially saying the StyleSheetManatger does not work at all? You can see from my code snippett has a <stylesheets> element.
Did you ever manage to solve this problem? I've got the exact same issue, and I'm wondering if there is anything I can do to fix it?
The RadStyleSheetManager is used to minify and combine resources of the RadControls (or custom skins for them). If you want to minify your own style sheets you have to perform what is described in this
You can also try to check in your code if you are in DesignMode and disable the RadStyleSheedManager.
Thanks for your comment, though am still having serious issues.
I've been through the steps in this page: www.telerik.com/.../stylesheetmanager-serving-external-style-sheets.html to allow my site to host the external CSS style sheets.
This is from my master page:
What are these telerik styles that are breaking the backend, would it be possible to share a screenshot, please?
You can try adding your CSS to the frontend theme. It combines and loads all the CSS in one request, that way you can avoid using the stylesheet manager. You can find more info here: Themes and Working with themes.
With the RadStyleSheet manager you can also try the following: Set it not to be visible by default and then in code check if the page is in NOT in design mode and if this is true then set it to be visible.
I am already loading the CSS and images through the frontend theme. (as described in your links www.sitefinity.com/.../themes above) . When I load the CSS files this way, the site looks correct and the backend also works, however the files are NOT combined into a single request, (which is the reason I have been trying to get the stylesheetmanager to work). If you can tell me how I can combine the CSS files that are loaded via the frontend theme to be combined automatically into a single request that'll solve my problem.
See the screenshots of "Working Backend" for a sample of what our backend page looks like, and the screenshot "Working CSS" too see how the CSS files are requested (as shown by firebug).
As soon as I remove those files from the Frontend theme, and put a RadStyleSheetManager on the master page, when editing the EXACT same page as above it now looks like following screenshots:
As you can see when using the stylesheetmanager, my stylesheets are now combined into single request (which is what I'd like), BUT the backend page is unusable.
I also have tried setting the visibility of the RadStyleSheetManager to false (by default) though this still doesn't seem to make any difference at all. The backend pages still render exactly the same way.
I'm having the same issue. Did you guys ever figure this one out? I've thought about adding the stylesheetmanager dynamically but I'm not sure of the side effects of this.
Nope we never got this sorted. Ended up just not using the rad style sheet manager, and had to manually combine the stylesheets. A bit frustrating, but ended up spending too long trying to get it to work without any success.
Thanks for the reply. I was wondering if something like this would work:
protected override void OnInit(EventArgs e)
// Every page should have a script manager and style sheet manager
if (Page.Header != null)
if (Telerik.Web.UI.RadStyleSheetManager.GetCurrent(Page) == null)
private Telerik.Web.UI.RadStyleSheetManager CreateStyleSheetManager()
return new Telerik.Web.UI.RadStyleSheetManager()
ID = "styleSheetManager"