At the end of the combining algorithm, there is JS code that is emitted into the response that updates the hidden fields variable once Sys.Application loads. While there is nothing wrong with the code, it should be wrapped in an if-then statement just like the Sys.Application.notifyScriptLoaded statement is. There's no sense in wrapping Sys.Application.notifyScriptLoaded in an if-then statement and then not place the anonymous function in one as well. They both access Sys.Application.
Comments: This ticket was filed for a pre-15.1 version of AJAX Control Toolkit. If this is still an issue in v15.1 or later, please create a new inquiry.
Comments: This ticket was filed for a pre-15.1 version of AJAX Control Toolkit. If this is still an issue in v15.1 or later, please create a new inquiry.