Hi @LunaFG, sorry to hear about this.
I have translated your question to English as this is an International forum, please post any replies in English and it will be easier for me and other users to assist you.
Do you receive any kind of error message when you try to open the camera app or does the image just turn up black? Also, have you been able to carry out a quick test of the camera in order to see if the hardware works as intended? To do this, find and tap Settings > Support > Xperia Tests > Camera.
You may also try clearing the data for the camera app. This will reset all settings for the camera app which might do the trick. Find and tap Settings > Apps & notifications > Show all XX apps > Camera > Storage > Clear data > Tap "OK" > Restart the phone.
Another thing you can try is to reboot your phone in safe mode to see if the camera app works better there. By doing this you can see whether this behaviour is caused by a downloaded app or not. For more information on safe mode and how to use it, click here.
If the same behaviour persists in safe mode, you might need to repair the software on your phone using a computer and Xperia Companion. Keep in mind though that a software repair will erase all user data, so make sure to do a backup before the repair in order to prevent loss of data.
Try these measures and let me know how it goes!
