Website Issues After Deleting Images

I deleted lots of old image files from my uploads folder in File Manager. The website was working fine prior to this and is still working fine MOST of the time. However, there are some exceptions.

When I access the media library while editing a post/page to insert an image, there are blank image boxes left in the media library and the loading icon keeps loading as if more images would appear but nothing happens.

The second problem occurs when trying to set a featured image for a page or post. I am unable to successfully set a featured image (after selecting one, it just never loads in the page/post editor interface), but after attempting to add a featured image, our website becomes inaccessible for a couple minutes — both the admin back-end and the public site. During this period of 1-3 minutes, when we attempt to access the WP admin backend or when visitors attempt to go to our website, the result is an error. After a couple minutes, the issue resolves itself and the site starts loading properly.

I don’t know how to fix this. Does anyone have any helpful insights to share?

• This topic was modified 4 years, 5 months ago by Jan Dembowski. Reason: Moved to Fixing WordPress, this is not an Everything else WordPress topic