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Hi everyone,
I don't know what i have done.. but all of a sudden my messaging icon disappeared from my home page and main manu.
everytime i try sending a text to someone from my contact list i get this message
You seem to be trying to send a WhatsApp message to a phone number that is not registered with WhatsApp.
Your account mudt have WhatsApp installed in order to chat to WhatsApp.
If this was done automatically, it is likely that WhatsApp is the default messaging app.
Press "SMS" to send a normal SMS to this contact, press "invite" to send an invitation, or press "Reset" to restore default messaging app setting.
i pressed SMS but the same message keep coming up over and over again. Also, i selected Reset but nothing happens.
i've reset my phone through "Factory data reset" but i still can't find the messaging icon.
and when i enter a number and select "Send text message"
i get the same message above and when i uninstalled WhatsApp i got this message:
unfortunately, the process com.sonyericsson.android.soci alphonebook has stoped
plzz help me
* I can't recieve any text messages
hmmm. i doubt it,
is there any other way to reinstall the original software ?
i see, so the phone is second hand? or like given as brand new>?
you can
1) relock your bootloader
or
2) try this
http://talk.sonymobile.com/thread/38251
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oopps! lol
wrong thread, yes , i do thinkk that actually, sorry uli.
second hand
I see, the previous owner must have modified the phone beforehand... see the link uliwooly has posted above, and try to do those steps.
This is how to relock the bootloader
http://forum.xda-developers.com/showthread.php?t=1324703
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Ok, i will follow the steps thank u 
keep us updated
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