Tapestry Error in Joomla Open Source CMS

I am experiencing a tapestry error in my content management system (CMS) using my Joomla open source CMS. I am using it to publish content on the world wide web.
Whenever I upload something like content, videos or images, or when I do system updates. I am using the version of Joomla 1.6.0. My session automatically closed when I encounter tapestry error. What can I do to resolve and prevent the problem?
