A large number of pics/pdf's imported to Media Library no longer display


I recently discovered that hundreds of pics (as GIFF, PDF, JPG, MP4, etc) no longer show in the Wikis or even the Media Library. Their correct file name appears when you click on the link within the Wiki and even in the Media Library, but the image or video is not appearing.

This problem was first observed after the WP update that fixed the problem of hackers being able to get into the site as Admins if they registered as a user when permissions for new users is set to "Contributor". However, it may have been before that and I may have just not seen it.

We have a over 2000 images and PDFs in the Media Library. The affected files are from 2015 and include all uploaded in May, June, July, some in August (not all) and 1 in Sept (imported Sept 2, 2015). They represent over 10% of our Media Library. I ONLY use the UPLOAD box within the Wiki or within the Media Library to import pics, videos and PDF's.

Every time we create a new Wiki, we always View (not Preview) the Wiki to make sure everything shows up correctly, so I am certain they were all OK until sometime in the past two months. I do not know the exact date it started, because we have over 1200 Wikis, and add more every week. But I am certain that when the Wiki was created, they were all OK.

I am using Minimaze theme, and have been since long before this problem occurred. I do not have any "Gallery" plugin activated. We are using the default Media Library in WP. I do not recall adding/activating any new plugins during this time. However, since the WP patch to fix the hacker problem identified above, many of my plugins have had numerous updates . . . many more than in the months prior to when that WP patch was released.

I am going to paste some screen shots in the next post.

I have enabled Support access. Please help!!!!

Mary Todd