AccessViol after moving from 15.2.18 to 15.2.25

[joelcc]

I am doing a check in TController.IWServerControllerBaseBrowserCheck( aSession: TIWApplication; var rBrowser: TBrowser);

var
  luas : String; // UserAgentString

begin

  luas := Lowercase(ASession.Request.UserAgent)

I now get an accessviolation when I try to access the UserAgent.

Any ideas?