Gaming "You cannot use online with this game cart"

[homework]

I hate to keep making threads for support, but I don't know why all these things keep happening.
I went to go online on Pokemon X and it said "You cannot go online with this game cart". Any ideas what it means and how do I fix it?

 

[homework]

Anyone know please?

 

[Deleted member 333767]

Is there an error code associated with the error message, like "002-0123"?

 

[VirusX2]

May be Wrong region Cart...

 

[RedBlueGreen]

You'll need to give more information.
Legit game or flash card? If it's a flash card which one is it? If applicable have you applied a private header? If applicable have you trimmed the ROM?