why some app wont work on 3g on my lumia 720?

[WPCentral Question]

all my apps work fine on wifi. But when i use 3g my only few apps work.. not even internet explorer works... can any one solve my problem?

 

[Harrie-S]

In SETTINGS > mobile + SIM did you switch on Data connection ?
Did you use up all your data already fot this month?

 

[cpt sparrow]

well ofcourse i turned it on...
no i didnt use it all....
but still it apps like fb, gmaps, etc wont work

 

[Harrie-S]

How could I know that! And what if I now asked if you allowed these apps to use wifi only or how good is your 3g coverage or ... Is it again ofcourse