Thank you for all the additional information you have provided. Your website is running Sitefinity 3.x. To avoid getting returned to the login page please make sure that you have the following configurations:
1) On IIS, go to your website and check authentication settings. You must have Forms and Anonymous authentication enabled. Other types of authentication must be disabled.
2) Make sure that your website's web.config file has the bellow highlighted setting:
3) Set up a machine key in the web.config
of your website. You can use this tool
to generate the config section.
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items