When I run my tests in Visual Studio individually, they all pass without a problem. However, when I run all of them at once some pass and some fail. I tried putting in a pause of 1 second in between each test method with no success.
Any ideas? Thanks in advance for your help...
It's very possible that some modifications/instantiations done in one test affect the others. That indicates poor test design and lack of proper isolation.
It's possible that you have some shared data. Check for static member variables in the classes in use that means one test sets a value that causes a subsequent test to fail.
You can also debug unit tests. Depending on the framework you're using, you should be able to run the framework tool as a debug start application passing the path to the compiled assembly as a parameter.
as per the other responses. It sounds like you have a singleton or a global variable that is causing the interaction.
Everyone is probably right, some shared date is being modified between tests. But note the order of MS Test execution. Simply pausing between tests is not a solution. Each test is executed in it's own instance of the test class on a separate thread.