runtime error

So here I was on a Friday afternoon with another doozy of an error. I recently needed to make a modification to an existing web application we wrote. The original developer had left the company and I had to take this project over for the change. The forms make use of Ajax, so I duly went ahead and installed the Ajax Control Toolkit via NuGet. I then started seeing the following error: ‘JavaScript runtime error: Unable to get property ‘UI’ of undefined or null reference’. I saw that a modal popup caused this error. I wasn’t too surprised as I had expected some errors, but the solution however did surprise me. (more…)