Image preview function broken regardless of theme

I’ve only seen this topic up once here although it does not seem to apply to my case.

I have been using a theme for a while with no problems and all of a sudden images in the media editor cannot be rotated. The preview doesn’t show up and the error I get is “Could not load the preview image. Please reload the page and try again”

I tried removing spaces like the solution recommends but it doesn’t seem to work – also even if I switch to a different theme the problem persists so it cannot be theme specific (this function previously worked on both themes).

I tried reinstalling wordpress through the dashboard and that doesn’t seem to work either.

any ideas? I’m not the most technical user but this is really stressing me out!

NOTE: Not sure if this is related but a few weeks ago when my blog loaded it was showing an error page about uploads.php – so I looked for uploads.php in the theme and couldn’t find it – To get rid of the error i opened wp-config.php and removed the uploads.php requirement

is there anyway I can just re-install all my php files from scratch (but keep all the blog content of course)?