"Update Admin Set password='123'" -> error. Because the name of any field is not named "password"

Have you checked to see if any of the other apps ( the ones that are doing the inserts and updates ) are open and running. If there running in exclusive mode your never going to be able to connect they need to be running in shared mode.

You should check to see if one of the other applications ( the ones that you say are inserting and updating data ) are running and if they are what mode are they running in. If they are open in exclusive mode you're never going to get connected. They need to be open in shared mode.