Refer to the FAQ number 6 in this post, you can understand the definition for the offline and online.
Meanwhile you may also check the FAQ number 7 for the distinguish of the reset default program and upgrade firmware.
For the current issue that the robot doesn’t function when control it, may we know what’s kind of the batteries do you use?
Please kindly change the battery for the robot first have a try.
According to our test and research, it is suggested to use rechargeable Li-ion battery or rechargeable nickel-metal hydride, nickel-cadmium which can be bought from amazon or local shop. Or Alkaline battery with good quality like Energizer, DURACELL.
As for the issue that no response when code for it, once still the same issue after changed the battery, please kindly paste the picture for your program, thanks!