We are using MediaWiki 1.16.0 and our website was fine in November. I was able to upload materials onto our website. At the end of December as I went in to upload new information I noticed that our web page no longer showing what we had posted before. When I logged into the web page and went to the edit area all the coding is still there and everything that we uploaded was still there but it is not displaying on the website. What can we do to fix this?
Topic on Project:Support desk
You can contact your hosting provider and ask them what they changed. Also note that MediaWiki version 1.16 has dozens of security problems nowadays as you are using an ancient unsupported insecure version. You should upgrade: Manual:Upgrading
MediaWiki 1.16.0 requires PHP5. Has your webhost upgraded to PHP7? Your wiki's Special:Version page may show what version of PHP your server is running. Maybe check that?
I guess that this is your problem: Manual:Errors_and_symptoms#All_pages_have_no_content,_but_when_editing_a_page_the_wiki_text_is_there.
As said already - even if your problem should be a different one -, please do an upgrade of your old, insecure version.