My first problem on my 8700 shows error 507 on screen so i used the 8700M_PBr4.2.1_rel163_PL2.3.0.81_A4.2.1._Vodafone_ belgium_(Promximus)
after finishing loading my phone now shows error 543 ,
what i found out that the O.S is not loaded and under application wizard you will SYSTEM SOFTWARE And Core APPLICATIONs is not highlighted but are checked!
Please take a look