Safari Extensions keep on getting deleted I recently upgraded to High Sierra and I liked the upgrade too but the most annoying thing is that the safari extensions which I download from the official Apple website keep on getting deleted by itself I have tried to fix the problem by trying the following stuff:

Deleting  ~/Library/Safari/Extensions/Extensions.plist
Deleting  ~/Library/Safari/Extensions/  

So can someone help me around with this problem?
Most likely: Another case of self-corrupting but never correcting caches. 


Close Safari.
Remove ~/Library/Caches/com.apple.Safari (the entire folder  and its contents, where mismatching copies of the extension pile up with a pattern of name-1.safariextension, name-2.safariextension .)
Restart Safari. 
Download the extensions you need once more.
Extensions should stay put again.