Tests pass when run individually but not when the whole test class run

Question

I have solved a topCoder problem for which all the tests pass when I run them on their own. Nonetheless when I run the whole test class some of them fail. Could you, please,

Answer 1

I would like to add my experience regarding this issue.

After doing many debuggins I could confirm that there is no garbage data in the DB and also no static variables effects to the functionality.

And also the same unit tests, pass individually and all at once as expected in another environment.

Java versions, MySQL versions are the same in both environments. The only difference was the maven version. So, I configured the same maven version which was used in the successful environment.

Then after issue solved.