Mobistar c2 imei problem

Mobistar c2 unknow baseband and invailid imei.

I have tried sn write tool and maui meta latest but not success.

mobistar c1,c1 light,c1 shine and meny more model have done this tool.

but alwayes c2 is not success.what is reason I dont understand.

I have allready flashed formet all+download then write but not success.

Please guide me senior member,I am new for this field. Thanks in advance.