Exist is correct, not Exists. When you're typing in the whole line and put a '.' in all the available methods for that type of object should appear in a drop-down menu. That's probably the easiest way to check things like this.
Also, I'm guessing it should either be ("innertext:=Login Failure.") or ("outertext:=Login Failure.") Use object spy - the icon looks like Sherlock Holmes and is at the far right at the top (in the Tools Toolbar). Using that you can select the WebElement you want and find the text in the right-hand column matching "Login Failure." Then just look at whatever is in the corresponding left-hand column. That's what should be where "text" is now in your line WebElement("text:=Login Failure.").
Hopefully this was helpful and wasn't insultingly basic or anything. I'm new to all this stuff too but I'll try to help if I can.
Have a nice day!
Also, I'm guessing it should either be ("innertext:=Login Failure.") or ("outertext:=Login Failure.") Use object spy - the icon looks like Sherlock Holmes and is at the far right at the top (in the Tools Toolbar). Using that you can select the WebElement you want and find the text in the right-hand column matching "Login Failure." Then just look at whatever is in the corresponding left-hand column. That's what should be where "text" is now in your line WebElement("text:=Login Failure.").
Hopefully this was helpful and wasn't insultingly basic or anything. I'm new to all this stuff too but I'll try to help if I can.
Have a nice day!