I am testing my apex class and my test returns a "System.QueryException: List has no rows for assignment to SObject" error. I run the same query in my explorer and it returns the values. What could the problem be?

Hello,

I registered for a developer account, because wanted to test Miletone PM.

I installed and everything was very smooth.

Now wanted to test with different users so i did the following:

1. Created a new User with User License Salesforce Platform and Profile Standard Platform Users
2. The user received the email and activated.
3. But when i login with the User Credentials cannot see some of the tabs even if i set the Tab to Default On in the Profile
4. I cannot make the new users see the custom objects.
5. If i try to change the ownership of a Project to the new user it says that he must have read permissions in the object.

CAn somepne help?

Thanks in Advance