If you get the error The engine is not found followed by "The engine has been found" then this is a completely normal event. When the user interface is started, it checks to see if the engine (the service) is started. When the computer is started it can take some time until the service get started, so you can ignore this error. Now, if the "Engine is not found" error is the only one you get and the mushroom in the tray has a light red background, the you have a problem. Things to check:
1) If the program is installed as a service, then this means that the service has not been started. Often this is caused by a login error. If the service is set up to start under some account, and you entered the wrong password then you will find the description of the error in the EventViewer. Just re-enter the user name and the correct password and restart the service. This can be done from the control panel or from the user interface (Options-General-Service and Application control)
2) Another possibility is that you are trying to start the service under an account that has an empty password. The default policy in some Windows versions is that a service cannot be started with an empty password.
3) If the program has been working fine for some time and suddenly you are getting the "Engine not found" error, you probably have changed the password of the account that is running the service. Just re-enter the new password in Options-General-Service and Application control and restart the service.
4) Another possibility is that the service (or the application engine) is crashing for some reason.