The Dangers of Not Paying Attention to Software Prerequisites

What to do if you get a Method not found error in the LENS Alert Agent...

The other day I was doing a demo of LENS using someone else's laptop. This is a bad idea in most situation, but I was in a hurry. I think that's the first excuse of every software developer whenever something goes wrong. Everything was going well until I tried to switch servers, at which point I received the following error.

Method not found: 'Boolean System.Threading.WaitHandle.WaitOne(Int32)'.

Have you ever been in the middle of a demo and have your own code crash in front of everyone? It's not pleasant. Fortunately, I knew exactly what the problem was. In setting up the demo, I had neglected to check that the .NET Framework 2.0 SP2 was installed (see my April 10 post for more information). It had .NET 2.0, but not SP2. The installer correctly detects .NET 2.0, but fails to complain if SP2 is missing. Upgrading the system to SP2 solved the problem.

The moral of this story is twofold:

1. Always verify the system requirements before installing software. Don't expect the installer to be smart enough to detect subtleties like which service packs are installed.
2. Try not to use other people's PCs when doing demos in front of customers.

I intend to fix this issue in the next Alert Agent release, and hopefully make the installer "service pack aware." In the meantime, should you receive the above exception, you'll know how to fix it: just install .NET 2.0 SP2.

Note: you may also install .NET 3.5, SP1 which contains .NET 2.0 SP2 and provides additional functionality for other (newer) applications you may install.