Widget sidebar

Whoa!

That doesn’t look quite right…. There appears to be some missing markup because the sidebar is setting much higher than it needs to be. How are you making the changes? Ideally you want to be using a child theme.

I would say re-install Twenty Sixteen and make any further changes with a child theme. That way when the theme gets updated you won’t lose those changes. ??

Taking a slightly longer look it looks like the site-header is causing that because it is set to fixed

Hi Jose, thank you for your answer. I’m still new to this.

I added a child theme following the instructions you send, but now my website is all white. Do you know why the mother theme is not used?

a mother theme is just a building block, no need to use it (nothing wrong)

now you might have to build functions, widgets and most imortant CSS rules

By adding the child theme my site disappeared. Now that I changed the theme back to twenty sixteen it is still black. Does somebody know what I did?

What files does your child theme contain?

Are you able to share those? I would suggest using https://gist.github.com/ since it works better for posting large snippets of code than these forums. ??

A child theme really only needs to have the style.css file.

A quick look at the code does show that it stops right after the analytics script. Try deactivating all your plugins to see if that brings back your site. ??