I've set up webmin and it was working fine until yesterday.
I was trying to get it more secured. So I tried to put .htaccess with basic password authentication in the directory related to webmin.
However it didn't work at all. so I just enabled SSL for webmin.
This could be matter.
However now, File Manager in webmin won't work! It just shows "Inactive plugin"
How can I get it work again?
Here's the answer, as described on an Apple discussion forum:
sudo /usr/libexec/PlistBuddy -c "Delete :JavaWebComponentVersionMinimum" /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/XProtect.meta.plist