Share your experience!
PS only social media apps I got is Facebook and Snapchat.
I don't got Flickr, Twitter, Instagram or anything like that.
I don't have the 9gag app anymore either.
Been to the folder now and nope, nothings there.
I do cleare cache which is usually the problem.
What I'm a about to suggest might take a while to assess, but under Settings > Storage > Apps, does the total amount equal about 10GB? Should be enough to look at the top 25 apps if you sort by size. If it isn't the same I suggest you perform a factory data reset. Make sure you first create a backup using Xperia Companion
How much of the internal storage is shown as used if you connect your phone to a PC?
There is an obvious bug in the storage settings calculation where data stored by apps on the memory card is still counted in the internal memory calculation.
I have a 64GB SD card that is almost full of music cached by the Play Music app and you can see that the calculation is completely screwed. Apparently my internal storage is 4x full!
Hi @Kokinos
The following might help (translations may be slightly incorrect, I use the German version):
Go to Settings - Apps - press the 3 dots in upper right corner and select "show system apps" - scroll down till you see "save&restore" (or similar). This app might use 5GB or more, you can simply clear all data and then you should have your GB's of free memory back.
Background:
The automatic safety copy doesn't work for me either since 6.0.1, but every time it tries to run (it keeps sticking at 50% for hours) it occupies around 0,5GB of additional internal storage.
I therefore disabled "App" in the save&restore app menu, then at least the backup of the rest goes through within seconds and the app does not use excessive memory anymore.
Hardy66
Thank you so much guys,
I will try everything when the weekend comes and I have time to be a human 
HARDY IT WORKED!
Thank you!
I just cleared out 6,19GB!
Any comments on how dangerous this is in terms of backup?
Isn't there a online backup?
Should I do something manually to secure my data and my app-settings?