Hi @Khalay, let me see if I can help out here.
What exactly does the error message say when you try to use the main camera? Also have you been able to carry out a quick test of the camera in the support app to see if the hardware works as intended? Find and tap Settings > Support >Xperia tests > Camera.
Firstly i would suggest that you try clearing data for the camera app in order to reset all settings for the camera app. In order to do this, find and tap Settings > Apps and notifications > App-info/Show all XX apps > Camera > Storage > Clear data > Tap "OK" > Restart the phone. Your previously taken photos will not be affected by this measure.
Another good idea is to try to reboot your phone in safe mode and see if the main camera works while in safe mode. All apps downloaded from play store is temporarily disabled while in safe mode and by doing this you can see whether this is caused by a downloaded app. For more information on safe mode and how to use it, click here.
If none of these measures manages to improve the functionality of the main camera I suggest that you try to perform a software repair using a computer and Xperia Companion. Please note though that a software repair will erase all user data, so remember to do a backup of your user data first in order to prevent data loss.
Try these measures and let me know how it goes!
