This is a known issue in Sitefinity 3.5 SP1 (1747).
This has been fixed in Sitefinity 3.6. We would recommend you to upgrade your project with the latest Sitefinity version (Sitefinity 3.6 SP1 Hotfix - 1927).
Work around: You should remove the "~" symbol in the "href" attribute in the html code and the name of the project:
<a href="/name_of_ the_project/name_of_the_page.aspx"
If you have any problem, don't hesitate to contact us.
the Telerik team