Because many users have this problem ,but only because they didn't follow guides thrue the end,I decide to help them with this simply tutorial.When you recive this error from your phone:
please contact your
network provider or
that means - you didn't finalize flashing with CUSTPACK.Look here SonyEricsson Hardware and Firmware Definitions! - Top Sony Forums and you will understand all.
FOR XS++ USERS
So,if you use XS++ read part 4 of this great tutorial XS++ 3.1 Guide-Flashing, Customizing, Recovering - Top Sony Forums and finalize flashing,but if your phone isn't on the list or your region isn't there you need to do next steps:
1. Find CUSTPACK that match with your FS file (if you use EUROPE_2 FS - than you need EUROPE_2 CUSTPACK)
2.Unzip CUSTPACK and you will get folder /tpa/
3.Put that folder in XS++ folder /own_custpack/
4.Start XS++,connect phone and select Customize file system.Instead you pick your phone model - select "own_custpack"
5.Now, if you do everything wright - hit FLASH and thats it.
FOR SETOOL2LITE USERS
1.Find CUSTPACK that match with your FS file (if you use S_E_EUROPE FS - than you need S_E_EUROPE CUSTPACK)
2.DON'T unzip CUSTPACK - in Setool goes ziped and than follow this tutorial Flash your phone and How to apply or remove patch using SETool 2 Lite - Top Sony Forums
PART 2 - STEP 4 to the end
FOR jdflasher (FAR Manager)USERS
1.Just follow steps from 8. to 13. from this tutorial Flash K800 CID53 with K810 software CID53 (for begginers) - Top Sony Forums by @senter
That should be solved yours problem with Configuration error and your phone will work just fine.