The server tag is not well formed error occurs because you have missed to write something or written something wrong. In my case i have written one link button and it gives me the server tag is not well formed error.
My link button is as follow
It gives me error. Actually everything is right but i have done small mistake in Text. Correct link button text is as follow
Text='<%# Eval("studio") %>'
It is working perfectly after replace double quote to single in Text. Because of Eval use we have to use single quote not double quote.
Hope it will help you too.